Merge pull request #621 from bvssvni/master

Updated links in README
remove files keyboard.rs and mouse.rs; now living in the input lib
Merge pull request #623 from mkcp/master

remove files keyboard.rs and mouse.rs; now living in lib piston-input
Added sample count to window settings
Merge pull request #626 from kvark/msaa

Added sample count to window settings
Renamed stuff

Closes https://github.com/PistonDevelopers/piston/issues/625