Allow "No Transition"

[Bauxite-camcom]

It is sometimes needed to allow an event to be processed and no state transition, such as timeout in receive message, and then resend.

[bikingcoder]

I agree. There's no valid reason to consider this an error if you have explicitly constructed the FSM to accept these transitions. At a minimum it could be a configuration option? @maxekman

I've noticed that the callbacks are still performed, which makes returning an error even more strange.