Move font face class out of font files.
Move load font face code to font face classes.
Move free type font face to FontFaceFreeType.
Move save bitmap font to FontFaceBitmap.
Add FontFaceBitmap and FontFaceFreeType files.
Remove unused class declaration.
Fixed missing include.
Fix typo.
Remove unnecessary check for physics world (2D).
Merge font-refactor.
Remove friend class declaration.[ci skip]
Removed unnecessary cases of MarkAnimationDirty() in AnimatedModel to allow manually positioned bones persisting correctly on scene load, when there are no animation states.
For Travis CI - switch CI build to use OS X build environment.