Editor: Improve layout of user settings dialogue
Possible improvements:
- Expand the section selection panel (left side) so that there is only a minimal border between it and the top/left/bottom side of the window
- Make the window resizeable, but force a minimal size to ensure the window stays functional
- Add a vertical scrollbar to the right panel, if necessary
- Add a vertical scrollbar to the left panel, if necessary
- Make elements in the right panel align to the top
- Generally improve the layout of elements in the right panel
(RM-1965 from redmine: created on 2014-10-03 by Marc Zinnschlag, , closed on 2014-10-19 by Marc Zinnschlag)