[feladat @ 73] All owners (not sub-owners though) of the zone are now shown when listing a zone. Added a new function to retrieve owners of zone by id without fetching all other zone details, which should improve perfomance. Both fixes by Peter Beernink.

[feladat @ 72] After a user had logged out, the menu bar was still shown until a reloading the login screen. [Fix: Peter Beernink]

[feladat @ 71] Improved printing of revision information in footer.