Added cooldown to units
No more spamming. Cooldowns work.
Added a cooldown test
Merge branch 'master' into enforce_cooldowns
Fixed the bug where units that were selected would die but not be removed from the selected list, essentially becoming invisible units with invisible bullets.
Merge pull request #54 from hellochar/enforce_cooldowns

Enforce cooldowns
Fixed a bug in master
Merge branch 'master' into 12-player-support