Make g_mount_spec_to_string generate a "nicer" string
Make g_mount_spec_to_string generate a "nicer" string

We'll be showing this of publically as the id of metadata databases, so
it better be somewhat shorter and nicer.

halfline/gvfs,xkahn/gvfs-cmis,philipl/gvfs,halfline/gvfs,gicmo/gvfs,philipl/gvfs,halfline/gvfs,xkahn/gvfs-cmis,thiblahute/gvfs,gicmo/gvfs,xkahn/gvfs-cmis,xkahn/gvfs-cmis,cpatulea/gvfs,philipl/gvfs,cpatulea/gvfs,thiblahute/gvfs,gicmo/gvfs,gicmo/gvfs