Merge tag 'upstream/2.1'

Upstream version 2.1
Merge tag 'upstream/2.1.1'

Upstream version 2.1.1
Merge remote-tracking branch 'origin/launchpad'
New upload to m.d.n.
Update debian/control:
- package kde-config-gtk-style-preview now breaks old package
  kde-config-gtk-style (Closes: #698285)
- package kde-config-gtk-style-preview now recommends package
  kde-config-gtk-style
New upload to m.d.n.
New upload to Launchpad.