autolaunch uuid support

[Havoc Pennington]

Thiago Macieira wrote:
> It breaks execution of dbus-launch --autostart without a parameter. 
> dbus-launch doesn't complain. Attached a patch to fix it. I had intended 
> to write this all along anyways.
> 
> I also could not build D-Bus without the second attached patch. I didn't 
> investigate why it happens: _dbus_abort is undefined.
> 

Thanks for looking it over - both of these patches look good to me.

Havoc