Now `AcediaGameRules` are only added when Acedia actually needs their
events.
AcediaCore now also outputs console message about adding them and
registers a side effect.
This patch changes AcediaCore to only inject `BroadcastEventsObserver`
when its events are actually needed.
Other changes are making this change produce a log entry and adding a
relevant `SideEffect` that describes this change.
I shamefully ended up doing another mega-commit, because a lot of things
needed to be redone at once and it was easier that way on me. No one
really consistently tracks what I'm doing with these commits anyway.
This adds a whole bunch of code to deal with proper clean up for Acedia,
so it doesn't crash on map change and also replaces old event/listener
system with new signals/slots one.
Anton Tarasenko