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.
Refactor signal/slots system for more efficieny and better user
interface that allows to disconnect receiver like so:
`OnEvent(receiver).Disconnect()`.
Some of the broadcasting events only properly work with full injection
method (`BHIJ_Root`) and some additional work was required to implement
them for `BHIJ_Registered`.
Althought support for `HandleText()` and `HandleLocalized()` events
cannot be perfect with `BHIJ_Registered`, current method should work
good enough for most cases.
Give it a more meaningful name `BroadcastEventsObserver` and teach it to
support 3 different way to add itself into the chain of
`BroadcastHandler`s: at the very beginning, through a regular
`RegisterBroadcastHandler()` method or simply do not add it at all.
Anton Tarasenko