* Switch to autpkgtest since tests require fonts.
* Drop all patches, no longer applicable due to kf5 port.
* Demote kde-config-gtk-style-preview from recommends to suggests.
recommends by default suggests is the relationship of choice.
- Remove build dependency on libgtk2.0-dev and libgtk-3-dev.
* Package moved to unstable after tests: no changes required.