https://github.com/KhronosGroup/glTF/issues/183
Fix skinning
First pass on https://github.com/KhronosGroup/glTF/issues/155
added normal map import + shader generation support when combined with point lights.
Full supporting coming next.
Add GLTFExtras placeholder
Add light attenuation for Point light
Fix lightning
Fix again lighting
Fix leftover of previous min/max implementation
https://github.com/KhronosGroup/glTF/issues/184
simplify point light
Support combination of normal map and directional lights
Clean up
Hopefully clarifies shader generation WRT lights
Fix Skinning and clean up some constants
Support for Phong and experimental spot light support
Update OpenCOLLADA version
First pass on spot lights
Merge pull request #282 from KhronosGroup/v0.6-fixes

V0.6 fixes
#260
KhronosGroup/glTF#68