Changed distance calculation to treat space as a torus
Uhh changed to use vectors instead of passing around lots of x's and y's
Uh changed to use vectors to store positions and velocities
Merge branch '0.3' into 0.3.vectors

Conflicts:
	cells.py
	main.py
Ugh this is three times slower than without the Vector class but at least its fast with pypy
Fixed main.py that i broke
Nevermind it looks like Dalen's was faster because it didn't use toroidal distance checking and after fixing that both are too slow because cells won't cross the border to eat
Merge branch '0.3.vectors' into 0.4.dalen

Conflicts:
	cells.py
	environment.py
	main.py
	util.py
Merge branch '0.4.dalen' of github.com:NCFDev/cellular into 0.4.dalen