Began work on TextureAtlas support for BitmapFontLoader

-Added a field to the BitmapFontParameter
-Improved documentation a bit
Added support for BitmapFontLoader to load regions from TextureAtlases

-Not tested!
More support for loading BitmapFonts from atlases
Added a test for this PR
Added a test for proper disposal of resources
Added the resources for the BitmapFontAtlasRegionTest
Removed dependencies on the original font images

-Whoops, they shouldn't have been there in the first place
Added the Shape interface
Implemented Shape methods in Circle
Fixed missing closing bracket
Implemented Shape methods in Ellipse
Implemented Shape methods in Polygon
Implemented Shape methods in Polyline
Implemented Shape methods in Rectangle
Removed unnecessary methods and optimized getCenter() in classes
implementing Shape
Removed a redundant implementation of centroid calculation
Renamed Shape to Shape2D
Added annotations support to class and field reflection wrappers.
Added GWT annotation emulation layer. Currently supports String and String[] member types only.
Added GWT support for class, enum and primitive type annotations.