libblkid: DRBD support for blkid

libblkid: DRBD support for blkid

DRBD is the Distributed Replicated Block Device, a replication service for low
level block devices.

The attached patch provides libblkid detection for v08 type drbd devices
(v08 is the current one).

[kzak@redhat.com: - port to libblkid 2.17
                  - use BLKID_USAGE_RAID flag
                  - remove BLKID_IDINFO_TOLERANT flag
                  - note that DRBD is supported since kernel v2.6.33-rc1]

Signed-off-by: Bastian Friedrich <bastian.friedrich@collax.com>
Signed-off-by: Karel Zak <kzak@redhat.com>