Instead of doing it via push/pop on the style context at draw time.
This way we will be able to specify and propagate some font style
to the monitor label, since style fonts are per-widget.
In the previous design of this panel, it made sense to show the
currently selected monitor because all editing widgets were in
the same page. With the new design, however, the monitor options
were moved to a separate page, and that page already shows which
monitor is being edited.
Remove the colored background of selected monitors.
This commits adds a new arrangement widget, refactoring the existing
code and addressing a number of issues:
* Forced snapping made laying out more than 2 monitors hard
* Random gaps would be shown between monitors
* The scaling was fixed and usually tiny
https://bugzilla.gnome.org/show_bug.cgi?id=786971
