manager: filter out wayland user sessions if X11 login screen
We use wayland by default on the login screen, so if we're running
in an X11 session, then the presumption is that we're incapable of
using wayland. If we're incapable of using wayland sessions then
we should ignore wayland sessions read from user configuration and
fall back to non-wayland defaults.
libgdm: filter out wayland sessions from X11 login screen
We use wayland by default on the login screen, so if we're running
in an X11 session, then the presumption is that we're incapable of
using wayland. If we're incapable of using wayland sessions then
we shouldn't present those sessions to the user in the session list
either.
This commit makes sure to avoid showing wayland based sessions
in the session list if the login screen is running on X11.
custom is a magic name we used to allow
for having the user decide their session by
a ~/.xsession file. We no longer support that
construct and haven't for many years. Instead,
users who want that functionality can just add
a xsession file to accomplish it.
This commit just removes some left over cruft that
never got cleaned up.