* Add operator[] to ConcurrentMap which returns a TValue reference
* BTTV/FFZ channel emotes are now stored in the Emote Manager, and each Channel object has a reference to their own BTTV/FFZ channel emote map.
* Restructure EmoteManager a bit (simplify the ConcurrentMap havoc).
* Add EmoteData struct which can store emote data (for now only messages::LazyLoadedImage*)
* Add CompletionManager that does nothing
- Remove some underscore-prefixes
- Start using this-> more
- Remove a few of the singletons (We pass references to managers to
things that need it now. Might not be much better, but for now
it works. It also shows what places might be slightly wrong
designed)
