LU-1182 ofd: add space accounting support

LU-1182 ofd: add space accounting support

Add space accounting support to OFD. This is done by calling into the
lquota library which looks up space usage via the accounting objects.
Report success on quotacheck, quotaon & quotaoff for the time being,
otherwise space accounting can't be tested with current MDT stack
which requires quotacheck to be run for space accounting to be
enabled.

Signed-off-by: Johann Lombardi <johann@whamcloud.com>
Change-Id: I442f3d1bcc9e7c95bb3f505f7a00665419d0f517
Reviewed-on: http://review.whamcloud.com/3186
Tested-by: Hudson
Reviewed-by: Niu Yawei <niu@whamcloud.com>
Tested-by: Maloo <whamcloud.maloo@gmail.com>
Reviewed-by: Andreas Dilger <adilger@whamcloud.com>