start to add weapon selection
Merge branch 'master' of https://github.com/tompudding/spacefight3000

Conflicts:
	hud.py
Merge branch 'master' of https://github.com/tompudding/spacefight3000
weapon selection work
Merge branch 'master' of https://github.com/tompudding/spacefight3000
set a troop in level 1 to have a lazer and a zooka
adds a weapon switch and the ammo works properly.
Merge branch 'master' of https://github.com/tompudding/spacefight3000