Merge pull request #8 from breaks/master

Added bullets feature (no collision detection yet), fixed for merge
make bullets update clientside, make server update 100ms instead of 10ms
(syncs better with clients)
add push-back to bullets fired by humans that hit zombies, most bullets
miss because of client/server desync though
add limit to bullet firing (15 bullets every 5 seconds), add checkbox to
disable zombie mode
remove rooms (for now), make server/client movement code use delta times,
add disable zombie mode option, make client resync when tab switched
todo: fix client desync when they're a zombie hit by a bullet
fix zombies that are shot desyncing
Implementing keyboard controls (only shooting works at the moment)
Updating with master