attribute.
(delete_x11_socket): Deleted function, folded into...
(do_kill_x11_socket): ... deleted uid-changing code.
(server_x11_listen) Deleted function responsible for uid changes.
open_x11_socket is sufficient.
(server_x11_setup): Deleted user argument. Use the display number
instead of the user name when forming the name of the Xauthority
file. Use the new function spawn_shell.

Rev: src/server_x11.c:1.21.2.2
Rev: src/server_x11.h:1.7.2.1