[libvirt] [PATCH 0/3] Take 2 - Patchset to avoid uid problems in volume creation

The first patch is unchanged. The 2nd and 3rd patches reflact Dan's suggestions. (wrt Cole's concern about the pool object being unlocked during the buildVol call - Dan pointed out that this is read-only usage of the object, and it can't be deleted while in use, so it's safe to pass it in here.) Note that I've tested this as much as I can with my own rig plus some DEBUG statements and small code changes (in particular, forcing creation of volumes on local filesystems to use the code intended for netfs), but testing on real NFS (as well as Samba to see if it solves that problem too) would be very much appreciated.