Added Mob spawning and path following.

Changed the default tile direction to be DIRECTION_RIGHT. Used simple
circle shapes to act as mobs. Created the path for mobs to follow. Mob
speed is based on the amount of frames.
Fix Buy Tower if end bracket is missing!

I resolved conflicts, but the end brace looked like it was removed for
some reason unknown.
Merge remote-tracking branch 'origin/master'

Conflicts:
	game.js

Nate Resolved Conflicts