lxdm: initial add 1.22_git

* use git version since 1.21 missing escape button and bugfixes
* no init-scripts (I am working with systemd -> testing causes huge efforts ->
  subsequent patches)
* run tested on overo/xfce

Signed-off-by: Andreas Müller <schnitzeltony@googlemail.com>
Signed-off-by: Koen Kooi <koen@dominion.thruhere.net>