Initial commit
loading spritesheet and about to render tile textures
-initial loading of spritesheet and rendering, still buggy though
-added property to specify spritesheet
rendering palette properly now
Extending ImageButton for PaletteTile now instead of extending Table
Can add tiles to be rendered in the world now
-Rendering a tile cursor where next tile will be created upon clicking
-Aligning tile placement to snap to grid
-Reverting GDXPolygon changes that were from original intent to extend
it with GDXTile, now GDXTile is standalone
-Clearing tiles when clear is pressed 
-Rendering grid only in view port
-Satisfying the overlord by purging Sprites from all GDXTiles, thereby
allowing them to be properly serialized
Loading tilesets (of different sizes) properly now
Including sample spritesheets and example screenshot
Merge pull request #24 from mattchaney/master

-Merging #24 Tile Mode current status, WIP