GNOME Shell emits a warning when "url" is absent in metadata.json,
adding it costs nothing. Links to the GIT repository because I
found no better page to reference.
Modify workspace management to only remove empty workspaces at end,
which is more consistent with a fixed workspace layout.
Also, some whitespace cleanup.
Patch provided by Thomas Bouffon <thomas.bouffon@gmail.com>
First of all, remove windows that are not interesting (like popup
menus and tooltips). Then, queue once an idle if the app is null,
in the hope that ShellWindowTracker picks up the window.
Introduce a new extensions that allows to manage your workspaces
more easily, assigning a specific workspace to each application,
as soon as it creates a windows, in manner configurable with a
GSettings key.
