FlxG.addBitmap() bugfix when FrameWidth or FrameHeight equals to zero
optimizations and fixes (origin related) for drawing
#105: Add possibility to support TexturePacker format
#105: Initial support of TexturePacker format

- FlxSpriteTex - FlxSprite for TexturePacker atlas
#105: Fix FlxSpriteTex for flash target
#105: Fix FlxSpriteTex.getAtlas

- check is BitmapData for _bitmapDataKey is null