deadlock when invoking transition from inside of another transition

[UnquietCode]

There is a deadlock because the outer transition holds the lock, and as part of the action a new transition is called. Clearly this is bad behavior, but the deadlock is somewhat off-putting. It should be possible to async transition this way, but that seems to be broken.

• support using transitionAsync from inside of a transition
• support transitionAsync from inside of transitionAsync (naturally)
• try to detect when inside of an existing transition and throw an exception instead of deadlocking