rescue+extra: whoops, fixed a thinko

I was crazy not to recheck this :-(
services: pass service status to installer

This is long overdue: services feature influences live
and rescue but doesn't do anything to the installed system
as that's behind the installation barrier; some piggybacking
required to do that has been merged into installer back in
2012 apparently (thanks to boyarsh@ for both doing that and
bringing my attention to this fact; it's 65-setup-services.sh
as of today).

So the only thing missing has been the bridge to prepare
those files -- still some more tweakery is required given the
two-stage process arranged so that reusable configuration could
include some sane defaults but the release manager is ultimately
able to override anything without extra kludges; thank legion@
for his wonderful libshell either.

NB: install2 script is a partial clone of rootfs one since
processing the variables is identical; still rootfs script
has to change service state directly while install2 one
has to deposit the information for installer to handle.
server: disable dbus, lvmetad

"messagebus" service is autostarted since dbus gets in being required
by wpa_supplicant <- alterator-net-wifi <- alterator-net-eth; it is
really not needed in the minimalistic server, let's just turn it off.

"lvm2-lvmetad" service requires setup to be actually useful (#29474).
live.mk: initial live-glxgears image

This might belong to test.mk actually but it's been instrumental
in getting bumblebee support operational within these LiveCDs;
icewm and sysvinit are a commonplace among those currently
but aren't set in stone for that matter.
x11: optimus support

The use/x11/nvidia/optimus target will pull the bits required
to operate NVIDIA Optimus GPU scheme which relies on integrated
GPU to actually drive the screen; much thanks to barssc@ for
good walkthrough: http://altlinux.org/optimus

NB: this *will* break if nouveau gets in, YHBW.
live: tweak usergroups list

"cdrom" is rather obsolete (currently unused), and "xgrp"
is useful (and actually required to use bumblebee package).
live.mk: FG needs a mixer!

It's been done and taken into regular-icewm already,
and running FlightGear with whispering sound isn't
really immersive.
live.mk: added Tu-154 aircraft model to FG image

There's a beautiful airliner model out there thanks to the guys
at flightgear.ru, and it was asking to be included but its unclear
licensing status; now that 3.0 is GPLed I'm glad to add this package.
live.mk: FG needs network too

TerraSync might come handy (just as online manuals) but one's
going to need internet access for that so let's put at least
DHCP-over-Ethernet configuration preset in.
1.1.24-alt1

- service bridge
gear-store-tags