Better jumping, muting, start of collision detection.

Optimised jumping a wee bit, but it's not 100% efficient. Npc's now
shoot out from your body. Added Muting - press 'M' to mute! This can
easily be implemented into a pause menu etc. Some other improvements
too.

I also tried starting collision detection. Feel free to remove any code
you feel is absolutely pointless. (Most of it probably is)

Apologies for cluttering up the project!