Compose tree with other tree

Behaviors on its own do provide good compose ability on its own. Big behavior trees are surely possible, but suddenly you can realize that some part of that tree can be reused in other tree you are building. Copy&pasting that part is no good way to go.

Because of that Chief brings subtrees on the table. It's very simple in it's nature. There is a Subtree native behavior which is essentially considered a leaf, but it accepts treeId configuration which is then executed. If you examine code of that behavior, you'll see there is hidden magic behind it and can easily define own subtree behaviors, eg. executing tree used in many places often.

Minor change in this release is also regarding debugging of execution. Instead of whole chief namespace, you can filter out messages for chief:tick giving you only details about what subject was executed and result states of nodes.