Merge ConnectionEstablishedEventHandler and ConnectionLostEventHandler into one handler which takes a boolean.
Adapt old connection status handling code to use the new handler:
- Require a handler in the constructor since the UI of plugins should always display a warning which tells people to install WOT if it is not running. (Fred does not support dependencies of plugins yet so we cannot enforce it to run)
Make FCPClientReferenceImplementation non-abstract:
- Refactoring is finishd. It should compile again now.
- Next step will be to compile-fix DebugFCPClient to work with the new FCPClientReferenceImplementation architecture.