Added skeleton evaluation. Link's mesh now draws correctly (no material).

- Moved skeleton evaluation to it's own function, Update(). Removed joint code from DrawScenegraph()
- Parse explicit skeleton from scenegraph at compile time. Save joint's parent per-joint.
Added textures and samplerstates to the interpret/compile/load pipeline.
- Separated pointers that are only used for GFX initialization (and are only needed between load() and the first draw()) to their own structure so that we can reorganize easily later.
- All texture data for the model is now written out to "originalfilename.tex". Textures in the JSON store their offset into this file.
- Fixed bug in Framework3/Imaging/Image.cpp that prevented the parent from maintaining control of image memory.
Added full material support. Shader HLSL is included in the JSON file, but compiled at load time.

- Added HLSL synthesis functionality to Interpreter. HLSL is now written out to the JSON file
- Fixed missing nullptr initialization that causes failure (bad free()) when JSON parsing fails
- Fixed off-by-one error in tex1 that would skip the first texture and overflow
- Imported mat3 changes from BMDLoad to BMDRead
- renamed color1, color2, color3, colorS10 to more accurate names
- exposed GC3D functions to convert gc constants to Framework3 constants