Unit config for melee range

With a reasonalbe default of 0.8 meters instead of 5 meters
A general game balance tweaks

Fixed a bug in zombie AI with melee attacks
Rebalanced melee strength for zombies
Changed the Zombie Apocolypse gametype to spawn faster but less per round
Moved ownership of ambient light from Map class to Render class
Added day/night cycle
Merge branch 'master' of github.com:TheJosh/chaotic-rage