Add initial packaging of MATE Desktop Environment (#1012)

Notably it has a loading delay (~30s) issue with marco (MATE window manager).

main/postmarketos-ui-mate/APKBUILD

@@ -0,0 +1,21 @@
+pkgname=postmarketos-ui-mate
+pkgver=1
+pkgrel=0
+pkgdesc="(X11) MATE Desktop Environment, fork of GNOME2 (stylus recommended)"
+url="http://mate-desktop.org/"
+arch="noarch"
+license="GPL3+"
+depends="mate-desktop-environment xorg-server dbus-x11"
+makedepends=""
+install="$pkgname.post-install"
+subpackages=""
+source="start_mate.sh"
+options="!check"
+
+package() {
+	# Autostart via autologin on TTY0 (until we have a display manager #656)
+	install -D -m644 "$srcdir"/start_mate.sh \
+		"$pkgdir"/etc/profile.d/start_mate.sh
+}
+
+sha512sums="a5a48821538b18069bad6528d488ed2dd5ae7d4f4fa095215c30d5399a41e645300f0c70bef1178be085e5fe8510fb4dda5446585663fd57193e938558b803de  start_mate.sh"

main/postmarketos-ui-mate/postmarketos-ui-mate.post-install

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+#!/bin/sh
+
+# Autologin on tty1, let busybox autoconfigure 2-6
+autologin="$(getent passwd 1000 | cut -d ":" -f 1)"
+for i in 1 2 3 4 5 6; do
+	old="^tty$i::respawn:/sbin/getty 38400 tty$i"
+	new="# tty$i::respawn:/sbin/getty 38400 tty$i"
+	[ "$i" = "1" ] && new="tty1::respawn:/bin/login -f $autologin"
+	sed -i -e "s.$old.$new.g" /etc/inittab
+done
+
+

main/postmarketos-ui-mate/start_mate.sh

@@ -0,0 +1,15 @@
+#!/bin/sh
+
+# Mate autostart on tty1 (Autologin on tty1 is enabled in
+# /etc/inittab by postmarketos-base post-install.hook).
+# This is a temporary solution, we'll need something like a
+# display manager in the long run (#656).
+if [ "$(id -u)" = "1000" ] && [ "$(tty)" = "/dev/tty1" ]; then
+	# Start X11 with Mate
+	startx /usr/bin/mate-session 2>&1 | logger -t "$(whoami):x11"
+
+
+	# In case of failure, restart after 1s
+	sleep 1
+	exit
+fi