ci: switch coverage to avahi/avahi

configure.ac: disable gtk2 and qt4 by default

Both GTK2 and Qt4 are end-of-life so don't enable them by default.

docs/NEWS: Update for 0.7 release

Updates for 0.6.32 release

Update NEWS for 0.6.32-rc

Avahi 0.6.31

Avahi 0.6.30

Avahi 0.6.29

Avahi 0.6.28

Avahi 0.6.27