Added sg_persist resource agent and ocft for it.

sg_psersist is a Resource agent that implements SPC-3 Persistent
Reservations (contribution from Evgeny Nifontov).

Customers with an active-passive storage setup using MD-raid1 need
to ensure, that the MD device is only activated on one system at a
time. While this is clearly possible with the existing Raid1 RA in
SLEHA-11, there is still the possibility that crazy system
administrators assemble such devices manually from the command line,
leading to a complete data-loss as a result...

Daimler is absolutely paranoid wrt/ to the integrity of the data
stored on their production relevant database systems, and therefore
requests that the MD mirror elements are reserved using SCSI
reservations. There exists an implementation of a resource agent
around the "sg_persist" Utility from the sg3_utils package.

Signed-off-by: Evgeny Nifontov
Signed-off-by: Liuhua Wang <lwang@suse.com>