Added comments to reflect the notes mentioned in issue #511
Merge pull request #603 from waterbearlang/511_adding_documentation

Added comments to reflect the notes mentioned in issue #511
update for text sprite
update for text sprite
update for text sprite
Merge pull request #607 from waterbearlang/textSprite

Text sprite
refactor sprite to have shape sprites

- tested with gist #9022245
- refactored PolySpirte to Sprite which can be an image sprite, text
  sprite, polygon sprite or circle sprite
- refactored class functions of Sprite so that it works for any type of
  sprite
Merge pull request #608 from CelticMinstrel/master

Some little UI tweaks
Merge pull request #609 from waterbearlang/shapeSprite

refactor sprite to have shape sprites