Significant updates to ZombieLevel

Changed ZombieLevel to handle char array instead of int. Added new
methods for finding player and zombie start locations. Added new
exception for if map doesn’t contain a player start location (should
probably be caught by Danny before it gets to me, though).

Important: Going to need some kind of collection for zombies. Trying to
think of best way to handle it. Will also need a way to distinguish
between linewalk and randomwalk zombies in the array.
Merge branch 'master' of https://github.com/Danny987/ZamZams

Conflicts:
	Zombie.java