void shutdown(int exit_code)
Shutdown the mud, setting the process result code to
<exit_code>, or 0 if not given.
Never use this efun. Instead if you have a need to shutdown
the mud use the shutdown command. You may be asking yourself,
if you're not supposed to use it why is it here? Sorry, I
cannot answer that. Its top secret.
The efun causes a privilege violation.
LDMud 3.2.11 introduced the exit code.
LDMud 3.5.0 made the efun privileged.
break_point(E), swap(E), privilege_violation(M)