LU-1842 quota: setup/shutdown qmt device

LU-1842 quota: setup/shutdown qmt device

The quota master target (QMT) is in charge of the cluster wide quota
settings. The QMT device is setup/shutdown by the MDT which then
forwards all quota requests to the QMT via a list of request/lock
handlers exported by the QMT.

Signed-off-by: Johann Lombardi <johann.lombardi@intel.com>
Change-Id: I0bd800d2996f5c3b9d861d4c6fbd70dabc3b2860
Reviewed-on: http://review.whamcloud.com/4126
Reviewed-by: Niu Yawei <niu@whamcloud.com>
Tested-by: Hudson
Reviewed-by: Alex Zhuravlev <bzzz@whamcloud.com>
Tested-by: Maloo <whamcloud.maloo@gmail.com>
Reviewed-by: Oleg Drokin <green@whamcloud.com>