Feedback button separated

As suggested in this weeks meeting:

In minimized sidebar: just above the user icon
When expanded: as a extra symbol with right alignment in the user menu button (so it doesn’t eat up space)

Also: make the button the same appearance (size and no text beside it) as the other (currently white one) on the top side of the menu, when it is minimized.

(from redmine: issue id 2307, created on 2016-04-07 by benjamin.fischer, closed on 2016-04-20)

• Relations:
  • parent #2295