client: Fix problem in get_quota_root with update parent and ancestor

The right "quota parent and ancestor link" will like this:

         *             *
ROOT<----D2<----D3<----D4<----D5<----F
  \     /  \____/     / \_____/     /
   \___/    \________/   \_________/

Signed-off-by: Yunchuan Wen <yunchuanwen@ubuntukylin.com>
Signed-off-by: Li Wang <liwang@ubuntukylin.com>
client: support listxattr for quota attributes

Signed-off-by: Yunchuan Wen <yunchuanwen@ubuntukylin.com>
Signed-off-by: Li Wang <liwang@ubuntukylin.com>
mds: Fix a problem with rstat refresh.

rstat.version seems will always be zero, so it will block
the broadcast routine for rstat refresh.

Signed-off-by: Yunchuan Wen <yunchuanwen@ubuntukylin.com>
Signed-off-by: Li Wang <liwang@ubuntukylin.com>
client: fix problem with move files between quota tree

Signed-off-by: Yunchuan Wen <yunchuanwen@ubuntukylin.com>
Signed-off-by: Li Wang <liwang@ubuntukylin.com>
test: extend quota test case

Signed-off-by: Yunchuan Wen <yunchuanwen@ubuntukylin.com>
Signed-off-by: Li Wang <liwang@ubuntukylin.com>