Send Transistion on stay in FSM

Implementation and test for #13970
This patch only notifies external monitors that a transition occurred, but it doesn't actually cause handleTransition(currentState.stateName, nextState.stateName) to be called, which I believe is the spirit of the ticket: https://www.assembla.com/spaces/akka/tickets/3970#/activity/ticket:

In other words, change this line to:

```if (currentState.stateName != nextState.stateName || nextState.notifies) {```

I have a use case similar to the original requestor. I'm building a phone system that often transitions to the same state, for example from Menu -> Menu or Announcement -> Announcement, using different configuration data. When entering each Menu state, I need to play an audio greeting. I want to have that instruction in an onTransition block, for example:

'''onTransition {
    case _ -> Menu => playGreeting()
}'''

If the currentState is Menu and the nextState is Menu, currently my transition will not be triggered.