Use git-version plugin.

Tidying

Switch to new Error Managers.

This is a little bit icky, but I can't see a nicer way to do it.

Tidy up PluginInfo a bit.

Split giant methods up, simplify logic in a few places.

Remove unused methods.

Add a sendmessage to Connection.

Add Invite to ServerInviteReceivedEvent.

Remove silly compareTo method.

Remove hacky plugin dependency injection.

Add hints to tell idea where generated sources are

This doesn't seem to actually mark them as generated, but they're
marked as source/test dirs which stops the annoying errors every
time you sync.

No need to subscribe now.

Remove showConfig from Plugin.

Rewrite the entire git-version thingy.

Remove temp loading of plugins.

Use streams for publish error deleted events.

Tidying up in ErrorManager

Stop FED using listeners.

Tidy up error list in ErrorManager.