- Fix issue with exporting Skin data causing missing vertexes in nifskope
   - add helper methods for collision related export.
   - fix crashes when exporting animation

Updated user's guide.

Updated Niflib to the latest XML which adds support for bhkMeshShape, NiMultiTextureProperty, NiRawImageData, and NiSequence.

Re-exposed TYPE constants and marked them NIFLIB_API, making the TypeConst function obsolete.  You now must use NiObject::TYPE instead of NiObject::TypeConst() again.

Moved TypeConst function implementation out of header file. Hopefully should fix GCC visibility issue.
Fixed GetIDString virtual function missmatch that was causing the name not to show up when the function was called from a NiObjectRef.
Added Python-specific operator functions to Ref to prevent the wrapper from crashing on Null Refs.

* Renamed python.h to pyniflib.h to avoid confusion with the python.h file from python installation.
* Updated python test script.
* Enabled many things again in the swig wrapper interface, to ease debugging.
* Added "using namespace std;" in Ref.h (as in the rest of the library)

WIP: trying to make smart pointers work again with SWIG; for the moment I commented out most of the SWIG interface to reduce wrapper size and compilation time while testing

Add my Casting operators back to the base Ref.  Also change the header guard so that it doesnt conflict with 3ds max's ref.h

Finished Skin API except for NiSkinPartition.  Part of this was making NiSkinData read-only with a new interface.
Fixed a bug in the SubtractRef function.

Had to revert changes to Ref.h.  They changed some Python syntax and would not compile.

Commented out functions written by Amorilia that I need to figure out how to fix.

Major update to python generation scripts and others.  Currently just namepace and mutable size members with appropriate generated code.

Added new files to VS project.

Moved all generated files to gen sub directory.
Renamed some generated files.

Added destructor which decrements reference count on any referenced object.

Noticed that I had forgot to include NiObject.cpp in my last commit... unfortunately I've already started splitting off classes into their own files so that's included in this commit as well.
I also noticed that I never implemented the member functions of Ref!  I still haven't, but I was just surprised it's been compiling without complaint.