Some work on the Felis celestial
Added black semi-transparent background to the pause menu so it is easier to read
Make debug circles around the player translucent
Added behavior-driven AI system; started integrating this into Felis.
Added looping behavior to Felis to attach him to the player.
Added player health regen
Refactor: Move behavior code from Felis to Actor.

Tweaked some of Felis's wait values.
Fix Felis behaviors
Refactor: Move some of Felis's behavior code into actor base class.
Started collision system and added collision prototype.

Also refactored the math and vector libraries a little and did some more work on Felis.