Upgraded to lastest piston
Upgraded to latest Rust-Empty
Added `EventGame` to itegrate with Piston
Added a parameter '&mut App' to command closure
Updated `README.md`
Updated `README.md`
Updated docs
Cleanup code
Merge pull request #34 from Coeuvre/master

Added `EventGame` to integrate with Piston, Added a parameter '&mut App' to command closure