Completed the AI for passive enemies.
Active AI Done
Added Comments to things
Agressive AI Done
Add ranges necessary for AI interaction
Add a NullAI that the factory defaults to when generating enemies

Easier than just always checking if the ai is null before doing anything
Refactored a few things
Add range methods and move aggessiveness to AI
Update visibility when notified with an actor from the world
Player's do not care about visibility with anything
Mark area to start looking for visibility of the actors
Merge branch 'AI' of https://github.com/nhydock/revert into AI
Add agro and walk required methods for ai
Passive and Aggressive AI should be fully implemented and working now
Only do aggressive behavior when agro, else try walking around
Enemy images for other ai types
Fixed the walk behavior in ActiveAI

Also added the additional methods to NullAI
Have EnemyAI react on hits
Added Agro flags to hit methods
Add generic update based on cycle time for enemy AI

Also change attackRate to be second based float time