Since TLCOS has been removed we should consider removing the control panel from the client.
For example, ThinStation 5.2 has the corresponding options available in the OS gui settings.
When trying to run `tlclient -c` on Fedora 27:
> Xlib: extension "XFree86-Misc" missing on display ":0".
The GUI shows but nothing except for the resolution has any effect.
This is preventing an upgrade of our X11 libs as Xf86misc has been deprecated and we use that in tlcontrol.
Tested simple client usage after changes, works good.
Relnotes also looks good.
Looks good. It seems to be properly removed, can't find any traces of it left. Other client commandline options still work well. Release notes look good.