x11: initial lxqt support

This is a sketch based on both lxde and razorqt bits.
regular.mk: initial regular-lxqt

Seems working already.
desktop+razorqt+extra: add lxqt tag

Renamed to desktop+lxqt+razorqt+extra
so that the name fits both searches.
domain-client: split into two targets

The "full" one adds Kerberos ticket watcher GUI
and sets up avahi service to start automatically.
regular.mk: use/domain-client/full in "rich" images

This is actually downplaying: the net effect is that
a few images continue to carry krb5-ticket-watcher
and have avahi service enabled by default while most
of the images have one "weird" item less on their menus
and a few hundred kilobytes less in total RSS.

These are not really needed by default in lightweight
distros sporting reduced application and services set,
and the heavier ones will take relatively less hit
by default while being more ready as ALT Domain clients
(which was the whole motivation behind adding the feature
and the corresponding pkglist).
rescue+extra: added gammu

This is a nice small text utility which is immensely helpful
when dealing with good ol' phones.
regular.mk: regular-rescue gfxboot warning

This should better lurk here unless someone (including myself)
either forgets or doesn't realize the inobvious chain of the
assumptions made for the read-only warranty to actually work.
1.1.36-alt1

- regular-lxqt
gear-store-tags