Merge pull request #102 from bvssvni/master

Added dependency to `event`
Added link to how to contribute

See PistonDevelopers/piston#715
Correct cube face winding in gfx_cube example.
Merge pull request #103 from Nitori-/master

Correct cube face winding in gfx_cube example.
Updating deform example for changes in drag_controller
Updating for rust-nightly slice change