live: factor out x11-autologin

Hardly belonged there in the first place and became a culprit
during armh branch development since it had to be forked in
an ugly manner; move to rootfs hooks and be done with it.

VM images will be able to benefit either *but* installed systems
might have some trouble when this is implemented:
http://lists.altlinux.org/pipermail/devel/2013-May/197447.html

Split off use/live/x11 as a common free/proprietary ground either
(this refactoring had to be performed in parallel with x11 feature
being revamped, diffs quickly became intertangled unfortunately).

features.in/live/README

@@ -2,3 +2,8 @@
 специфическими для полноценного LiveCD настройками
 и скриптовыми хуками, а также создаёт файл index.html
 с домашней страницей (редиректором) в корне образа.
+
+Графический вариант безусловно требует x11-autologin,
+при появлении необходимости обойтись без него можно
+временно продублировать содержимое цели и сообщить
+о таком случае.

features.in/live/config.mk

@@ -17,19 +17,17 @@ else
 use/live/rw: use/live; @:
 endif
 
-# a very simplistic one
-use/live/x11: use/live use/firmware use/x11
-	@$(call add,LIVE_PACKAGES,xinit)
-
-# optimized out: use/x11
-use/live/desktop: use/live/base use/x11/wacom use/live/sound \
-	+vmguest +power +efi
+# graphical target (not enforcing xorg drivers or blobs)
+use/live/x11: use/live/base use/x11-autologin use/live/sound +power +efi
 	@$(call add,LIVE_LISTS,$(call tags,desktop && (live || network)))
 	@$(call add,LIVE_LISTS,$(call tags,base l10n))
 	@$(call add,LIVE_PACKAGES,fonts-ttf-dejavu fonts-ttf-droid)
 	@$(call add,LIVE_PACKAGES,pciutils)
 	@$(call add,SYSLINUX_CFG,localboot)
 
+# this target specifically pulls free xorg drivers in (and a few more bits)
+use/live/desktop: use/live/x11 use/x11/xorg use/x11/wacom +vmguest; @:
+
 # preconfigure apt for both live and installed-from-live systems
 use/live/repo: use/live
 	@$(call add,LIVE_PACKAGES,installer-feature-online-repo)
@@ -49,18 +47,22 @@ use/live/install: use/metadata use/syslinux/localboot.cfg
 use/live/textinstall: use/syslinux/localboot.cfg
 	@$(call add,LIVE_PACKAGES,live-install)
 
-# NB: there's an unconditional live/image-scripts.d/40-autologin script
-#     *but* it only configures some of the *existing* means; let's add one
-#     or another for the cases when there should be no display manager
-use/live/autologin: use/live/x11
+# a very simplistic one
+use/live/.x11: use/live use/x11 use/x11-autologin
+	@$(call add,LIVE_PACKAGES,xinit)
+
+# NB: some implementation has to be added if it's not a display manager
+use/live/autologin: use/live/.x11
 	@$(call add,LIVE_PACKAGES,autologin)
 
-use/live/nodm: use/live/x11
+use/live/nodm: use/live/.x11
 	@$(call add,LIVE_PACKAGES,nodm)
 
+# see also http://www.altlinux.org/Netbook-live/hooks
 use/live/hooks: use/live
 	@$(call add,LIVE_PACKAGES,livecd-run-hooks)
 
+# a crude hack to make sure Russian is supported in a particular image
 use/live/ru: use/live
 	@$(call add,LIVE_PACKAGES,livecd-ru)
 

features.in/x11-autologin/README

@@ -0,0 +1,5 @@
+Эта фича добавляет в формируемый пользовательский корень
+(как правило, live) функцию автоматического входа путём
+конфигурирования отдельно запрошенного для установки
+display manager (например, lightdm) либо специального
+средства (пакеты nodm или autologin).

features.in/x11-autologin/config.mk

@@ -0,0 +1,3 @@
+use/x11-autologin:
+	@$(call add_feature)
+	@$(call add,THE_PACKAGES,shadow-groups)	# gpasswd

features.in/x11-autologin/rootfs/image-scripts.d/40-x11-autologin

@@ -21,6 +21,8 @@ backup() {
 	cp -av "$1" "$1$BAK"
 }
 
+## this is only relevant for installable livecd
+### FIXME: this shouldn't proceed in other cases!
 restore_later() {
 	[ -n "$1" ] || return 0