Now you can hook activation via GAbstractView::on_activation.
The design still isn't quite right, we should eventually move the selection
away from the model somehow.
This really brings the UI to life in a pleasant way. It's a bit annoying
that you can't initiate a resize by clicking on the shading of a splitter
resizer that actually belongs to the neighboring GFrame, I'm not sure how
to fix that yet but I'll think of something.
IRCChannel and IRCQuery objects now create their own windows with the
help of an aid_create_window callback provided by IRCAppWindow.
There's still a bit of murk but this is already an improvement.
