add x2go/xfce-debian docker image

* VDI server with temporary encrypted /home

docker/x2go/xfce-debian/setup_locales.sh

@@ -0,0 +1,9 @@
+#!/bin/sh
+set -eu
+
+LANG=${LANG:-C.UTF-8}
+LOCALES=${LOCALES:-${LANG} ${LANG##*.}}
+printf "LANG=%s\n" "${LANG}" > /etc/default/locale
+rm /etc/locale.gen && printf "%s\n" "${LOCALES}" |while read locale; do
+  printf "%s\n" "${locale}" >> /etc/locale.gen
+done && locale-gen