display settings widget template widget rewrite
Branch to rewrite the display panel as a template widget.
Mostly works, there are a few changes though:
- Display selection with more than 2 displays is now a GtkComboBox rather than something custom
- Margins are changed with the libhandy rows
- Some elements have been ported to the newer mockups
- Scale is currently just a HdyComboRow (it used to be buttons, but that is also broken, see MR !307)
Also relevant are:
- !314 (closed) (not addressed currently)
- #235 (fixed)