Merge pull request #71 from bvssvni/master

Fixed missing docs warning
Added link to how to contribute

See PistonDevelopers/piston#715
Fix for change to enum namespaces
Merge pull request #73 from gchp/master

Fix for change to enum namespaces
Renaming

Closes https://github.com/PistonDevelopers/input/issues/74
Closes https://github.com/PistonDevelopers/input/issues/75