Bullet Time

First attempt at implementing bullets from the player.  Still Problems:
Shooting up and to the left, bullets will disappear halfway to the edge
of the screen.  Shooting right, bullets pile up on the side of the
screen.  Shooting down works fine.
Merge branch 'master' of https://github.com/ChrisLHall/MakeRent

Conflicts:
	js/entities/entities.js
	js/resources.js