Update CMakeLists.txt

Add and modify notes about nearly incident points
Add links to Tomilov's qhullhull.hpp
Add note about scipy's use of Qhull
Suggestion: Add Octave's created endpoints for unbounded ridges [M. Voss]
FAQ and suggestions: post-merge pass for slivers [M. Treacy]
Add notes from Pavia and Zhang
Fix links

Make C headers safe for C++ inclusion.
Thanks for your good idea, well implemented.   --Brad

This commit moves the extern "C" { ... } logic into headers themselves.
This way, it's the headers responsibility to define it's linkage
appropriately and the consuming C and C++ code can both use "#include"
without ifdef guards.

 - Fixed memory leak in ~QhullQh [M. Sandim]
   QhullQh.cpp: call checkAndFreeQhullMemory() in the destructor.  Otherwise memT is not freed.
   Remove checkAndFreeQhullMemory() from Qhull.h.  It is not needed.
   Remove calls to checkAndFreeQhullMemory in qhulltest.  It is called by ~QhullQh()
   libqhull_r.h: Document qh_ASvornoi and facetT.center
   qh_freeqhull: if qh_NOmem, use qh_ALL
   qh_memalloc: short memory is freed by qh_memfreeshort unless qh_NOmem
   qh_memstatistics (mem.c): call qh_memcheck() as done in mem_r.c
   qh_new_qhull calls qh_memcheck
   qh_newvertex: free vertex on error
   qh_projectinput: Free memory allocations on error
   qh_rboxpoints: free simplex on error
   qh_sethalfspace_all: Fixed memory leak on error QH8032 feasible not inside halfspace
   qh_triangulate_facet: For TRInormals ('Q11') replace qh_copypoints with qh_memalloc
   qh_triangulate_facet: Document qh.TRInormals
   qh_voronoi_center: Free center on error
   qhulltest: Fixed memory leak of s_testcases by calling RoadTest::deleteTests()
   qhulltest: The 'add_*_test' functions append the test object to RoadTest::s_testcases
   ~RoadTest: declare virtual for Q_OBJECT, removeAll not needed
   user_eg2: Check memory at end of each run
   user_r.h: Add QHULL_CRTDBG for invoking Microsoft's memory leak detector
   use _MSC_VER instead of QHULL_OS_WIN for QHULL_CRTDBG
   Call qh_freeqhull with qh_ALL/!qh_ALL instead of 'True/False'
   Include user_r.h with RoadError,h for QHULL_CRTDBG
   Invoke _CrtSetDbgFlag... at beginning of program
   Moved user_r.h/libqhull_r.h/qhull_ra.h as first include (for QHULL_CRTDBG)
   Moved QHULL_OS_WIN from qhull_ra.h to user_r.h
   Removed __CYGWIN__ from QHULL_OS_WIN (same as Qt's qglobal.h)

 - check_dupridge: A bounding box is not sufficient to avoid dupridge errors
 - qh_findbestneighor: Error if qh.CENTERtype is qh_ASvoronoi (i.e., no merging now)
 - qh_printstatlevel: Remove unused parameter, 'start'
 - QhullLinkedList::last() and back(): Return T instead of T& (T is computed)

 - qh-code.htm: "How to convert code to reentrant Qhull"
   Update "Nearly coincident points on an edge"
   Add 2012 size of data structures to "Qhull on 64-bit computers"
 - html/index.htm: Add CGAL to "When to use"
 - qh-optq.htm: Add documentation for option 'Q12'
 - Move suggestions from Changes.txt to qh-code.htm#enhance
 - user_r.h: Fixed qh-us_r.html links
 - Fixed links in html pages

 - QhullIterator and QhullLinkedList: Include <iterator> [B. Boeckel]
 - Moved include file for each C++ source file to the top of the includes
 - Prepend cpp includes with "libqhullcpp/"
 - RoadLogEvent includes RoadLogEvent.h
 - QhullIterator.h: Only QHULL_DECLARE_SEQUENTIAL_ITERATOR is used.

 - Compared src/libqhull/* to src/libqhull_r/* and resolved differences
 - qh_printpoint in io.c skips qh_IDnone like io_r.c
 - qhull_p-exports.def: Added three missing exports
 - set_r.h: Removed countT. Too many issues

 - libqhull_r/Makefile: Add help prompts to 'make qtest'
 - libqhull.pro: Add '../libqhull/' to sources and headers
 - libqhull/Makefile: Fixed -I,./,,/src

 - qhull-zip.sh: Add CMakeModules to tarball [C. Rosenvik]
 - CMakeLists.txt: Add targets qhullp and user_egp for qh_QHpointer and libqhull_p
 - Reorganized 'make help'
 - Makefile cleanall: Delete testqset and qhulltest from bin/
 - Fix filetype of Unix-only files
 - Fix Unix line endings for Makefile and check in qhull-zip.sh
 - Fix Windows line-endings and check in qhull-zip.sh
 - qhull-zip.sh: Check for Unix text files

qh-impre.htm: Reworked "Nearly coincident points on an edge"
Move suggestions from Changes.txt to qh-code.htm#enhance

 - Add Rbox option 'Cn,r,m' to add nearly coincident points.  Trigger for duplicate ridges
 - Add Qhull option 'Q12' to ignore error on wide merge due to duplicate ridge

 - qh_findbestlower: Call qh_findfacet_all to fix rare "flipped or upper Delaunay" error QH6228.
   QH6228 input provided by J. Metz.  Reported (date order): L. Fiaschi, N. Bowler, A. Liebscher, V. Vieira, N. Rhinehart, N. Vance, P. Shafer
 - qh_check_dupridge: Check if wide merge due to duplicate ridge from nearly coincident points
 - qh_initialhull: Fix error messages for initial simplex is flat
 - qh_determinant: increased 2-d and 3-d nearzero by 10x due to a counter-example
 - rbox: Add qh_outcoord() to output coordinates w/ or w/o iscdd
 - qh_meminit (mem.c): Add call to qh_memcheck
 - Compare libqhull/... to libqhull_r/... and resolve differences

 - Update builds for DevStudio (qhull.sln for msdev 2005..2009, qhull-32.sln and qhull-64.sln for recent releases)

 - qh-impre.htm: Add a section about precision errors for 'Nearly coincident points on an edge'
 - html/index.htm#geomview: Document how to install, build, and use Geomview.
 - html/index.htm: Emphasize program links and move related urls to end
 - qhull/index.htm: Emphasize manual, geomview, and imprecision
 - Fix documentation links in libqhull_r/index.htm
 - Add 'Functions' link to documentation headers
 - Change '<A>...</A>' to '<a>...</a>'
 - libqhull_r/index.htm -- Add instructions for configuring web browsers for source links.
 - libqhull_r/ -- Fix source links for ..._r.htm files

If this occurs, Qhull 2015.1 will report an error.  For Delaunay triangulations a
workaround is to add a bounding box to the input set.

html/qh-impre.htm
  Add a section about precision errors for 'Nearly coincident points on an edge'

html/index.htm#geomview
  Add instructions for building Geomview on Windows.
  Add instructions for using Geomview to view Qhull examples.

 - Fix return type of operator-> in QhullLinkedList and other collection classes [F. Jares]
 - Fix return types for QhullLinkedList
 - Fix return types for QhullPoints
 - Simplify return type for Coordinates::operator[] (same as QList)
 - Add const to operators for QhullSet::iterator and add documentation
 - Coordinates.h: Fix return types for operations of iterator and const_iterator
 - Drop use of Perforce changelist number in qhull_VERSION of CMakeLists.txt
 - Rename the md5sum files as *.tgz.md5sum instead of *-tgz.md5sum
 - Fix build dependency for testqset_r [asekez]
 - rbox.c depends on Qhull due to qh_lib_check which uses qh_version2 for error messages
 - QhullFacet_test.cpp: Annotate Qhull invocations.   Allows their repetition.
 - QhullFacet_test.cpp: Adjust epsilon on distance tests
 - Do not create libqhullcpp as a shared library.  Qhull C++ classes may change layout and size.
 - qhull-cpp.xml: Make a relative path to road-faq.xsl

 - In the libraries, exit() is only called from qh_exit().  qh_exit may be redefined.
 - Add qh_fprintf_stderr to usermem.c.  May be overridden to avoid use of stderr [D. Sterratt]
   Add usermem to testqset builds
 - Remove most instances of stderr/stdout from libqhull, libqhull_r, and libqhullcpp [D. Sterratt]
   qh_fprintf_stderr may be redefined.  qh_meminit and qh_new_qhull use stderr as the default ferr
 - qh_initflags: Use qh.fout instead of stdout for 'TO file'.  A library caller may define a different qh.fout.
 - qh_settemppush: Call qh_fprintf() instead of fprintf() on error.
 - Rename qh_call_qhull as "Qhull-template" from user.c.  Updated its references.

 - qh-code.htm: "How to avoid</a> exit(), fprintf(), stderr, and stdout"
 - html/index.htm: Fix table of contents for qh-code
 - libqhull_r/index.htm: Rewrite introduction to Reentrant Qhull
 - qh-faq.htm: Rewrite "Can Qhull use coordinates without placing  them in a data file?"
 - qh-get.html: Link to github
 - Remove qhull_interface.cpp from the documentation

- qh_new_qhull: default 'errfile' is 'stderr'.  outfile and errfile are optional [B. Pearlmutter]
- qh_new_qhull: returns qh_ERRinput instead of exit() if qhull_cmd is not "qhull ..." [B. Pearlmutter]
- qhalf_r.c,etc: Add clear of qh.NOerrexit
- global.c: gcc 4.4.0 mingw32 segfault cleared by adding comment
- usermem_r-cpp.cpp: Optional file to redefine qh_exit() as throw "QH10003.." [B. Pearlmutter]
  qh_exit() is called by qhull_r when qh_errexit() is not available.

- html/index.htm:  Add bibliographic reference to Golub & van Loan and annotated the source references
- qhalf.htm: A halfspace is the points on or below a hyperplane [D. Strawn]
- qh-opto.htm#n: Defined inside, outside, on, above, and below a hyperplane [D. Strawn]
- qhalf.htm#notes: Recast the linear program using negative halfspaces (as used by Qhull) [D. Strawn]
- qhull_a.h: Fix comment '#include "libqhull/qhull_a.h" [fe rew]

- build/qhull*.pc.in: Add templates for pkg-config (derived from Fedorra) [P. McMunn]
  https://bitbucket.org/mgorny/pkg-config-spec/src/c1bf12afe0df6d95f2fe3f5e1ffb4c50f018825d/pkg-config-spec.txt?at=master&fileviewer=file-view-default
- Makefile: Remove user_eg3.o from LIBQHULLCPP_OBJS
- Makefile: Add .h dependencies for unix_r.o, etc.
- libqhull/Makefile: Fix build of rbox
- libqhull_r/Makefile: Fix build -I
- qhull.sln/user_eg3:  Add dependency on libcpp

  Preliminary Qhull release available at http://www.qhull.org/news

 - Visual Studio builds for VS-2010+ 32-bit and 64-bit
 - Unix tarball includes version number (e.g., qhull-2015-src-7.1.0.1940.tgz) [Hauptman]
 - qhull -V -- Display Unix version number for qhull [Hauptman]
 - Update eg/make-vcproj.sh for vcxproj Visual Studio builds

 - README.txt: updated builds and reentrant Qhull
 - Add documentation for QHULL_LIB_CHECK
 - qh_lib_check: Check for unknown QHULL_LIB_TYPE
 - qh-code.htm: Add memory requirements for 32- and 64-bit

Accidently reverted merge from next

This reverts commit c27f1515.

This reverts commit c27f1515.

This reverts commit f06e487a, reversing
changes made to db490523.

Minor Conflicts:
	src/testqset_r/testqset_r.c

 - qh_mem, qh_merge: Log before 'delete' instead of afterwards [Coverity, K. Schwehr]
 - qh_merge: Test for NULL horizon in qh_checkzero [Coverity, K. Schwehr]
 - qh_matchneighbor: Check for matchfacet not a neighbor of facet [Coverity, K. Schwehr]
 - qh_triangulate: Explicit check for visible==NULL [Coverity, K. Schwehr]
 - qh_findbestfacet (unused by qhull): Fix test of isoutside [Coverity, K. Schwehr]
 - qh_check_maxout: Check bestfacet!=0 for logging its id [Coverity, K. Schwehr]
 - qh_nearvertex: Check for bestvertex not found [Coverity, K. Schwehr]
 - qh_checkfacet: Check for missing neighbors of simplicial facets [Coverity, K. Schwehr]
 - qh_setdelnth: Check 'nth' before using it [Coverity, K. Schwehr]
 - Annotate code for Coverity warnings (most of these protected by qh_errexit) [K. Schwehr]

 - qh_printfacet3math: explicit format string (duplicates change to io.c) [B. Pearlmutter]
 - libqhull_r.h: fix spelling error (duplicates change to libqhull.h) [B. Pearlmutter]
 - unix_r.c: fix spelling error (duplicates change to unix.c) [B. Pearlmutter]
 - qhull_a.h: define qhullUnused() only if defined(__cplusplus) [R. Stogner]
 - qh_version: Use const char str[]= "string" instead of const char * str= "string" [U. Drepper, p. 27]
 - qh_newvertex: Use UINT_MAX instead of 0xFFFFFFFF
 - qh_newridge: Use UINT_MAX instead of 0xFFFFFFFF
 - Reviewed FIXUP notes

 - QhullRidge_test: t_foreach use 'foreach(const QhullVertex &v, vertices)
 - Made '#include "RoadTest.h" consistent across all C++ tests

 - qh-code.htm: May also use libqhull_r (e.g., FOREACHfacet_(...))
 - qh-get.htm: Add list of download build repositories

 - Add CMakeModules/CheckLFS.cmake: Enables Large File Support [B. Pearlmutter]
 - Makefile: Use -fpic at all times instead of -fPIC, [U. Drepper p. 15]

debian quilt patches, forward ported

Moved 'to do' comments into Changes.txt

global_r.c: Fixed spelling of /* duplicated in...qh_clear_outputflags */ [K. Schwehr]

Enable LFS aka Large File Support (as option) in cmake.
Snag cmake LFS macro from
https://github.com/simongog/sdsl/blob/master/libdivsufsort-2.0.1/CMakeModules/CheckLFS.cmake

Avoid lintian error

  qhull-bin: manpage-has-errors-from-man

to whit

  usr/share/man/man1/qhull.1.gz 750: warning: macro `QJn'' not defined
  usr/share/man/man1/qhull.1.gz 771: warning: macro `Qt'' not defined

and consequent lost text.  These result from a line starting with the
single quote character; this patch backslash escapes them.

Fix FTBFS when building with hardening flags as used by dpkg 1.16.0.
Note that this was a *false positive* by the compiler: there was
in fact no security issue.  However we will work around it anyway.

Bug-Debian: http://bugs.debian.org/643461

    qhulltest OK
    make testall OK
    Qt, CMake, and make build OK

Summary of Perforce changes @1811,@1954 from Jan 17, 2015 to date
See src/Changes.txt

    Code
        Remove qhull_inuse
        Add qh_lib_check to verify library compatibility
        Change qh.vertex_visit, vertexT.id, ridgeT.id, qh.vertex_id, and qh.ridge_id to 32-bits
        *.c: Prefix include headers with directory name (e.g., libqhull_r/)
        user_r.c: Clear qhT.ALLOWrestart in qh_errexit
        global_r.c: Check that qh.NOerrexit is cleared before call to qh_initflags
             User must clear NOerrexit after setjmp()
        global_r.c: Add qh_zero to reset qhT before first use.  Needed for user_eg_r.c
        global_r.c: Add qh_lib_check() for library compatibility
        global_r.c: Add qh_zero() to initialize and zero memory for qh_new_qhull
        global_r.c: Version includes a '.r' suffix to indicate 'reentrant'
        global_r.c: Guarantee that qh->run_id!=0.  Old code assumed that qh_RANDOMint was 31 bits
        io_r.c: Commented out qh_compare_vertexpoint.  Not used and not implemented in libqhull_r
        mem_r.c: Add qh_memcheck() to verify memory buffers
        mem_r.h: Define ptr_intT as 'long long' for __MINGW64__ [A. Voskov]
        qconvex_r.c,etc: Comment-out _isatty declaration.  Avoids "C4273 ... inconsistent dll linkage"
        random_r.c:  Moved global variable qh_last_random to qhT.last_random
        rboxpoints_r.c: Replace longjmp with qh_errexit_rbox
        stat_r.c: Remove qh_freestatistics().  Part of qhT now.
        Rename 'int' to 'countT' where more than 32-bits may be needed
        Remove old code for __MWERKS__ && __POWERPC__
        Replace qh_pointid returns with qh_IDunknown, qh_IDnone, and qh_IDinterior
        Points are equal if same coordinates
        Add in-line comment about expected warnings (e.g., **freelistp)
        Remove vertexT.dim -- No longer used by C++

    Build
        Reentrant files are named with '_r' suffix
        Deprecated qh_QHpointer files are named with '_p' suffix
        Removed the 'p' builds for qh_QHpointer.  They were confusing
          Renamed libqhull_p.vcproj to qhull_p.vcproj
        Makefile: Reorganized targets: test, qtestall, and testall
        Makefile,etc: Changed to gcc -O3 (was -O2)

        libqhull_r/Makefile: Add 'make help' and 'make test'
        Use mingw-w64 instaed of mingw
        Use 'Win64' tag for CMake
        Removed Debian 'config' directory, doesn't work
        Removed qhull_interface.cpp
          'math.h' is apparently no longer a problem.  Perhaps include it before qhull_a.h
        Removed make-vcproj.sh -- too specific to VC 2005

    Doc
        See "C++ interface" in Changes.txt for notes on migrating C++ code
        Changes.txt: Add notes on 'countT'
        Clarified qhalf space documentation for the interior point [J. Santos]
        Rearrange qh-code.htm to emphasis C++ interface.  Move performance and wish list to end

    C++
        QhullFacet: Increment Zdistio statistic
        QhullHyperplane: Remove default constructor
        QhullPoint: Change operator==() to sqrt(distanceEpsilon)
        QhullPoints: Enable operator=()
        PointCoordinates: Add assignment of base class QhullPoints to operator=
        PointCoordinates: Rename point_comment to describe_points
        QhullQh: Add qh.ISqhullQH to indicate initialization
        QhullSet,etc: Include <cstddef> for ptrdiff_t
        QhullSet: Enable operator=.  Copy constructor and assignment only copies pointers
        QhullSet<T>: Add 'typename T' to definition of value()
        QhullVertexSet: error if qhsettemp_defined at copy constructor/assignment (otherwise double free)

        Delete Point_test.cpp.  It was replaced by QhullPoint_test.cpp
        Add QhullVertexSet_test.cpp to qhulltest.pro
        Moved UseOutputStream to a field with enableOutputStream
        Removed UsingLibQhuill*.cpp.  It is not needed with reentrant Qhull

Updates to libqhullcpp for libqhullr.

See Changes.txt for details.

Delete user_eg7,8,9 replaced by user_egp,2,3
Rename qhull_ra.h
Change spacing for type annotations to 'QhullVertext &' etc
Each class needs access to qhT via QhullQh
Moved messaging into QhullQh to simplify memory allocation
Add 'const Qhull &' constructors for C++ classes
Printing QhullRidge includes a message

Ran RboxPoints_test.cpp
Ran QhullPoint_test.cpp

libqhullr
  Renamed add *.c and *.h references to *_r.c and *_r.h
  Added *.htm from libqhull

Redesigned QhullPointSet around QhullSet<>
Ran QhullPointSet_test.cpp

branch qhull_r.h as reentrant version of qhull_a.h

Fixed qh_MEMalign for testqset and testqsetr

libqhullcpp will be based on qhullstatic_r
Runs user_eg3 on qhullpcpp ok

Ran OK the first time
Added rboxr

Includes libqhullstaticr and libqhullr