LU-1842 quota: remove quota code

LU-1842 quota: remove quota code

This patch removes the quota code (from quota directory, but also
from mdd & obdfilter) which is going to be replaced by the new
implementation.
This patch also modifies the mdt to use the new space accounting
scheme as already used by the ofd layer.
sanity-quota.sh now also uses ofd by default and only runs the space
accounting tests until quota enforcement support is landed.

Signed-off-by: Johann Lombardi <johann@whamcloud.com>
Change-Id: I85cbbf6058859e5d19f80aa128f45b6d41c37d92
Reviewed-on: http://review.whamcloud.com/4098
Reviewed-by: Niu Yawei <niu@whamcloud.com>
Tested-by: Hudson
Reviewed-by: Alex Zhuravlev <bzzz@whamcloud.com>
Tested-by: Maloo <whamcloud.maloo@gmail.com>