EggSMClient is no good

[Brian J. Tarricone]

Hey Nick,

I just noticed that EggSMClient doesn't support SmRestartImmediately, 
which is a bit of a showstopper.

It seems to support it based on GNOME's non-standard .desktop file 
extensions, by looking for an X-GNOME-AutoRestart key.  Obviously we 
don't support this.

I can attempt to whip up a patch for egg_sm_client_set_mode(), but it's 
gonna be kinda a hack.  What do you think?

	-brian