Upgraded to latest Rust-Empty
Upgraded to latest Rust-Empty

Closes https://github.com/PistonDevelopers/piston/issues/476

mitchmindtree/piston,getynge/piston,placrosse/piston,Potpourri/piston,PistonDevelopers/piston,bvssvni/piston,PistonDevelopers/piston,caldwell/piston,tempbottle/piston,axelmagn/piston,oldmanmike/piston,bvssvni/piston,KevinFrans3/piston