Merge pull request #5 from leomuona/master

camera funzies. black screen.
Oops... Fixed COLLADA node values parsing.
Send SDL_VIDEORESIZE event to trigger onResize event.
Various fixes to COLLADA parsing.
Rotate position around Y-axis.
Renamed loadJoints to load_library_visual_scenes.
Initial library_animations parsing from COLLADA.
There might be multiple samplers.
Save sid and id of each joint.
Documented semantic var from Sample struct.
Generic string split func, able to give delim.

Implemented load_animation_channels, target and source.
Started work on actually using the animation data. WIP.
Removed graphics adapter approach and instead created skeleton renderer interface design.