LU-1014 mountconf: MGS update timeout upon config update

LU-1014 mountconf: MGS update timeout upon config update

MGS should update obd/ldlm_timeout upon MDS/OST config update. It
will be the largest value of all servers.

Signed-off-by: James Simmons <uja.ornl@gmail.com>
Signed-off-by: Lai Siyao <laisiyao@whamcloud.com>
Change-Id: Ia0786475fa5608e06f8c2606f87f98192a870df5
Reviewed-on: http://review.whamcloud.com/2881
Tested-by: Hudson
Tested-by: Maloo <whamcloud.maloo@gmail.com>
Reviewed-by: Andreas Dilger <adilger@whamcloud.com>
Reviewed-by: Oleg Drokin <green@whamcloud.com>