libs/avahi: fixed mutating libavahi/avahi-daemon. The package was producing a package...

libs/avahi: fixed mutating libavahi/avahi-daemon. The package was producing a package avahi which required dbus if libavahi-dbus-support was selected (even as module), and without dbus if that package was not select. This has been fixed so that there are now dbus versions of the binary packages and non-dbus versions of the ones that can be without dbus, so that the smaller platformas can still have avahi without dbus, and those who want the dbus avahi can have it as well.

SVN-Revision: 27479