LU-73 lbuild and friends for RHEL6

LU-73 lbuild and friends for RHEL6

This adds the lbuild support needed to build RHEL6 servers.
Included is a re-org of the RHEL5 lbuild code to maximize code
reuse and minimze code replication.
The kernel config here is the stock config from an x86_64 RHEL6
kernel build.  It might need some tuning for Lustre.

Signed-off-by: Brian J. Murrell <brian@whamcloud.com>
Change-Id: If83ee846d6d84a456444fb54feba0ad7810a586a
Reviewed-on: http://review.whamcloud.com/332
Tested-by: Hudson
Reviewed-by: Michael MacDonald <mjmac@whamcloud.com>
Reviewed-by: Robert Read <rread@whamcloud.com>
Reviewed-by: Oleg Drokin <green@whamcloud.com>