"The XDG_CURRENT_DESKTOP environment variable can contain a list of
desktop names. The existing code assumed it could only contain one
name."

Solution by Robert Ancell

https://bugzilla.gnome.org/show_bug.cgi?id=739592

The current code blocks the UI thread briefly if the generator threads
do not finish in order. Oh and it's also not safe.

No clue what's going wrong here....

https://bugzilla.gnome.org/show_bug.cgi?id=737507

https://bugzilla.gnome.org/show_bug.cgi?id=737895

This would have been good to have known about earlier. :(

The double title looks awful and we can't fix it without a string change.

Using the title is better for both desktops, but let's avoid UI changes
in the 3.14 branch when we're not running in Unity.

Also, doesn't make sense to use ref for a reference-type paramater.