This changes Xsession and Xclients to call to the KDE Plasma X11
session binary directly, rather than assuming that "startkde" will
start an X11 session.
- Resolves#806491#990213#1006029
- Remove stale ck-xinit-session references from xinitrc-common (#910969)
- Make startx pass "-nolisten tcp" by default, use -listen as server
option to disable this (#1111684)
- Teach Xclients script about lxde (#488602)