LU-1842 quota: add quotactl support on qmt

LU-1842 quota: add quotactl support on qmt

This patch implements quotactl ({get,set}{quota,info}) support on the
QMT. This involves defining the lqe operations for the qmt as well as
pool operations in order to support per-pool quota in the future.

Signed-off-by: Johann Lombardi <johann@whamcloud.com>
Change-Id: I122e7cb85eb6d1d3460e86217e2a6723763c8cbf
Reviewed-on: http://review.whamcloud.com/4160
Tested-by: Hudson
Tested-by: Maloo <whamcloud.maloo@gmail.com>
Reviewed-by: Niu Yawei <niu@whamcloud.com>
Reviewed-by: Mike Pershin <tappro@whamcloud.com>
Reviewed-by: Oleg Drokin <green@whamcloud.com>