[Patch] Mount window closes on unmount if opened from Places or Desktop

[Luke Symes <allsymes gmail com>]

Due to the recent fix for Bug 318094 (close windows on unmount), there
is a problem when unmounting from a mount slot when you have opened it
directly from Places or the Desktop. Please take a look at my proposed
patch and the rationale for it at
https://bugzilla.gnome.org/show_bug.cgi?id=611569 .

Thanks,

Luke.