Preparing for openshift support

[rbo]

Adjusting images that they run without modifications in the Open Shift.

[rbo]

At branch rbo/openshift (only centos-xfce-vnc) it works, but is not perfect.
ToDos:

• Cleanup the Dockerfile
• Adjust ubuntu-xfce-vnc

[toschneck]

@rbo maybe the issue with the initializing of the UI environment is relied on the vncserver implementation we use. I had good experiences with tigervnc on my pc, where vnc4server and tightvnc had some problems. I think we should give tigervnc a try 😄

https://github.com/TigerVNC/tigervnc
Tiger VNC on Ubuntu xenial: http://www.hiroom2.com/2016/05/24/ubuntu-16-04-remote-connect-to-gnome-classic-desktop-with-vnc-xrdp/

[rbo]

Added new branch rbo/Issue_#3, all Dockerfiles works in openshift.

[rbo]

Update openshift templates & all merged into dev.