Enhance behavior tree support (or get rid of it)

[iskorotkov]

There is an action subclass that executes a behavior tree. BT execution doesn't stop the brain from making new decisions and can lead to multiple actions having effects at the same time.

Possible solutions are:

• Get rid of BT support (probably the best idea, but I need to provide support for executing a series of actions)
• Add time delay after BT execution (probably a bad idea)
• Stop making new decisions until BT finishes execution

[iskorotkov]

BT offers good functionality - I can't replace it completely, so I will have to enhance its support. So solutions 1 and 3.