Implemented EnemySpawner; basic spawning is working
Startin spawn rate/limiting
Removed testing code for enemy spawning
Made it possible to re start a level
Code cleanup, round starting, stage starting
Code cleanup, unused methods + docs
More code cleanup
Code cleanup, documentation
Added skeleton projectile class, needs more thought
Merge pull request #76 from zackthehuman/master

Enemy spawning implemented; code cleanup underway