Fix warnings.
Fix warnings.

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