Tweaks to enemy AI

Fixed some bugs with enemy running animation. Fixed bug with search
state, though the enemies still do a weird dance after they wait.
Optimized Raycasting

Changed the ray casting algorithm so it doesn't check every tile in the
level just the relevant tiles.
Tweaks for damages and enemy health

Made the different heroes do different amounts of damage. Also they have
different attack rates. Enemies have more health and shoot slightly
faster.