WIP C runtime.
Merge remote-tracking branch 'origin/master'
Fixed crash.
Added Atlas.
Compiles with C89.
Minor refactoring.
Added Animation.
OOP in C is a cold, dark place.
Got rid of the "key" in "keyframes".

We only deal with keyframes in all the animation stuff, it's cleaner without. Sorry if this breaks anyone! Easy fix at least.
Extension stuff seems to be shaping up nicely!
Renamed TextureAtlasAttachmentLoader. Was too damned long and didn't match spine-c.
Refactoring.
So close, but alas must sleep :( 5am!
C runtime works!
Better spine-c example.
Better spine-c example.
License headers.
Minor cleanup.
Refactoring for cleaner OOP.
Cleanup, docs.
Docs, cleanup.
Include guard.
Refactored loading files.