Slavek,
avahi-tqt for 3.5.13-sru just needs the qt-watch.moc3 fix backported, then it builds fine. The diff is attached. I can't find a commit in http://git.trinitydesktop.org/cgit/avahi-tqt/ that matches, so this just might need to be reviewed and signed off.
The reference for the fix is here:
http://trinity-devel.pearsoncomputing.net/?0::6608