Implemented Visibility Notifier system for perf of off-screen objects.

Added new actor type: Traps. First traps are a basic floor spike trap and a wall trap that fires a frostbolt.

Did a pass on Sword and Board Special Attacks. Now charges up for a big swing while blocking. Improved block anim.

Added keyboard functionality and key remapping for keyboard.

Added new weapon type: Throwing Axes. 

Did a pass on Maul's special and add a dash special attack.

Camera shake pass.

Added very first impact audio.

Reduced max creatures to 10 for testing.

Added new console line functions to set the max creature cap: "maxmonsters x"