header and NiNode for now)

* created a common swig interface "common.i" to be used by all modules

* smart pointers now use the __call__() method, again this reduces the
  wrapper size

* removed __str__() from the niflib API as it does not belong there,
  instead renamed asString() to __str__() in the common.i interface

* version constants now also belong to the Niflib namespace

* SWIGFLAGS are now defined through scons environment, so we only need
  to set them once

* extra settings "-fcompact" and "-fvirtual" to SWIGFLAGS to reduce
  wrapper size

* enabled niflib as a shared library under non-win32 platforms
  (still need to find a solution for win32) under scons

* removed "pyniflib.h" and instead added CreateNiNode wrapper to ninode.i

* renamed "pyniflib.i" to "pyniflib.i_old" in case I forgot to port
  something to the new modularized system; to be removed in future

Changed order of %include's: Ref.h is now %included before niflib.h. It looks like the problem with illegal return types under SWIG is solved. (Solution suggested by Shon.)

number of objects are supported so far, to reduce the size of the
wrapper. Details:

* set property eolstyle:native on .cpp and .h files for better windows + linux 
  support

* added small cpp file for quick nif read and write test (for
  debug purposes)

* fixed memory leak due to array of non-fixed sized objects:
  Header.copyright (caused segfaults under GCC)

* disabled pragma warning on NvTriStripObjects.cpp

* fixed undefined behaviour of map[...] = ... map.size() ... in
  niflib.cpp (caused segfaults under GCC)

* cleaned up SConstruct file
  - if DEBUG is false, TUNE is assumed
  - added TEST option

* workaround in pyniflib.h for ReadNifTree (need to find better solution!)

* swig wrapper interface: NiNode, NiAVObject, and NiObjectNET are
  fully supported (nothing else, for now)

* now using unittest for python test script(s)