[kpartx][libmultipath] make multipath and kpartx prefix the uuid

[kpartx][libmultipath] make multipath and kpartx prefix the uuid

In order for other programs to figure out who owns the dm-devices that
are created by multipath and kpartx, this patch adds a prefix to the uuid
for all multipath and kpartx created devices.  When multipath gets the
uuid,
the prefix is stripped back off. However other programs can use the device
mapper library or dmsetup to easily check which devices were created by
multipath or kpartx.

the multipath prefix is mpath-
the kpartx prefix is part%d- where %d is the partition number.

Ben Marzinski, Redhat