Scaling Backdrop properly for atlas rendering, related to #158
Adding 'any button' checks to Joystick.

Omit argument to check for any button.
Ouya home button + info

This information is pretty important.
adding CONTRIBUTING file
tweaks to contributing document
Formatting
visual tweaks to CONTRIBUTING
Merge pull request #219 from Nananas/dev

[ouya] 'any button' check and Home-button information for Joystick.
Consistent formatting
More minor formatting
Semicolon fix
Use optimized version of drawTiles to avoid shrinking draw array.