added importer for libgdx files
removed left over trace
Merge pull request #11 from RudolfVonKrugstein/libgdx-importer

added importer for libgdx files
Cleanup
Implement rendering with
* a single bitmapData for all frames
* a spritesheet

This is done using classes implementing the "IRenderTarget" interface.
Also this classes render directly into the graphics of  the AnimatedSprite
instead of a "bitmap" child of it.
clear graphics when drawing new frame
Added flags and flag to enable "ADD" BlendMode.
Also the given IRenderTarget now render to the graphics of a Sprite.
The display object is needed, so that BitmapRenderTargets can set the blendMode of the Sprite.