Tonight I mocked up some healthbars (they're just sprites, nothing dynamic yet) and added them into the game. Units can now get damaged, but are still unaware of the whole 'death' thing. I fixed a few bugs with the turn-based engine as well, so that's pretty solid for now.

Added a referencing system to behavior trees to make it easy to replace nodes with other nodes. I created a behavior for being in the bed, which basically does nothing until it's time to wake up. The interaction command for the bed now handles adding that behavior into the tree when he uses the bed; and then when he uses the bed to wake up, it clears that behavior. This will hopefully be one more piece of the puzzle for dynamic interactions that don't grow out of proportion, and while the bed behavior is not attached, none of those nodes have to be processed.

I may change some of the existing subtrees to use this attach-detach mechanism.