Goblin Behavior tree updates (Patreon)

Still getting all of the pieces put back together for the next build.  Which will have some new AI behaviors for the generic goblin encounters.  

I've broken encounters down by distance to the target.  The distances can also be customized per behavior tree or on the fly by a set of variables.  For this initial pass there's long, medium, and close ranges.  Long range will just trigger the goblins to run towards their target.  Once they reach medium range they'll randomly select between: leaping to try and grapple the target, using a ranged weapon, strafing around the target, or moving closer into melee range.  Then at close range they'll randomly select between: performing a melee attack, attempting to grapple the target, or stepping back to medium range.  

The randomization is all evenly weighted right now but I'm going to add weighted options so that the AI would be more likely to perform a melee attack rather than step away from the target for example.  

This also all ties in with the combat temptation scenes and supporting those events better.  Previously those temptation scenes would only trigger after a successful leap and grapple from medium range.  So if the AI was at close range then the player would never see those scenes.  

I also made sure to set everything up to be relatively modular and easy to test new behaviors.  That way tweaking individual behavior trees per NPC race should be straightforward as well as adding new behaviors in the future.