Behaviour manager now gone.

Behaviours dealt with by body, and by individual limbs.

Still need to figure out how to sort out this "drawSpecific" bs in
Tentacle. Maybe just create another creature, trying to use the
tentacleBehaviour, and see where that takes me.
Stuck regarding AABB and JBox2D.

Look at shiffman's nature of code and his PBox2D. I should probably
incorporate this instead of JBox2D. This is because of the coordinate
system problem. This may be why the AABB overlap / contains functions
aren't working. They *probably* still should work but I feel I've tried
everything. I should switch to PBox2D, use the coordWorldToPixels()
methods, and try this again.
Fixed bounding box problem. Correctly knows when colliding now.
Bounding box working correctly again.
Moving back towards having a behaviourManager, such that individual
parts don't have their own behaviours anymore.

So a virus will have a behaviourManager, and it can include a Move, a
Collide, a Hunt, etc.

I guess the limbManager separately takes care of the behaviours for the
limbs