Make Raw optional, mark some fields as @Nonnull.

Move mode alias reporting out of Server.

Doesn't really need to be there, makes more sense as a separate
observer which can do its own thing.

Improve some optionals.

These are absent when disconnected, so use optional instead of null.

Left most of the calls as-is - if something assumed parser was
non-null before it assumes the optional is present now. Should be
easier to clean up later.

Make the formatter set the FG property for events.

More BackBuffer work.

- Only show each event once, don't propagate to servers.
- Use a setting to control whether it's enabled or not.

Remove old getConnection() and rename new one.

Add a way to specify event colours.

Fix various deprecated uses.

Change-Id: I0bb97a8946d1c217de82fe2a9b8f35b7d49eae06

Add invocation ability to ConfigBinder

Move BackBuffer to ui.messages.

It doesn't really make sense in ui.core now it's doing more...
The classes it's integrating are all in messages.

Add back buffer entries based on events.

Switch action to use Paths.

Add a path for temp directory.

Any formattable DisplayableEvent received on a frame container's
event bus is now automatically added to the IRC Document.

Current problems:
  1) Every time this happens the old path still executes, so you
     end up with two lines
  2) Every event on a channel's event bus gets passed to the
     server's, so the lines appear there as well.

Give the BackBuffer an EventFormatter.

Urgh.

Make BackBuffer subscribe to events.

This is where displayable events are going to be added.

Tidy ErrorReporter test.

Remove NullOutputStream.

Add unit test for core action extractor.