[patch] out-of-process volume monitor

[David Zeuthen <david fubar dk>]

Hey,

In http://bugzilla.gnome.org/show_bug.cgi?id=520132 I've uploaded a
patch that 

 a) implements infrastructure for implementing out-of-process
    volume monitors; and

 b) port the hal volume monitor to use this

OK to apply? The patch is somewhat big (145k) but I've tested it and it
seems to work perfectly.

Thanks,
David