Minor cleanup.
Event timeline for spine-c, AnimationState refactoring.

closes #113
spine-tk2d and spine-unity updated to latest spine-csharp.

closes #120
closes #125
Compile with C89.
Nix printf.
Fixed AnimationState mixing.
spine-cocos2dx updated to latest spine-c API.

This has some API breakage, sorry. The new AnimationState now handles multiple "tracks", which makes it easier to apply and queue multiple animations at the same time, no longer do we need multiple AnimationStates.
Merged upstream changes