Migrate debug plugin to showOutput/showError.

Remove unused method.

Use events for some more plugin outputs.

This slightly changes how the logging plugin history window
works - instead of parsing dates and using DMDirc timestamps,
it just shows the logged timestamp like the backbuffer does.

As history tends to span several days this seems more useful.

Issue DMDirc/DMDirc#426

Fix systray plugin

Use events for raw data in/out.

Systray plugin was attempting to set the visibility of the main
window on the EDT, do this off the EDT.

Issue DMDirc/DMDirc#426

Switch some more plugins to use new events.

DMDirc/DMDirc#426

Make logging plugin use new events.

DMDirc/DMDirc#426

Fix some build warnings.

Add snapshot repository.

Because plugins depends on client, they need to be able to
find the client's transitive dependencies as well.

Plugin support for core changes.

With the removal of message sinks, the active window plugin has
nothing to do now. We can reimplement it much more simply
directly as part of the Swing UI.

Remove most deprecated methods in commands

Support for core changes.

Support for core topic date changes.

Pass initial window state to new clients.

This adds an 'initial state producer' to create the burst of
state clients will receive on connect, and serialisers for
WindowModels and BackBuffers.

Add a controller for websockets.

The handler can't be dependency injected (as it's created by the
framework) so, in order to minimise the amount of static
horribleness, pass in a controller which can do the actual work
and have proper dependencies.

Add basic websocket handler.

web2: Add dagger module, make port configurable.

Skeleton web UI plugin.

Now with working dependencies and webserver.

Add skeleton files for new web UI plugin.

Textpane background opacity

Add a title to the perform dialog

Also fix an invalid default option for the "background option"