Back port of http://review.gluster.org/10363

After attaching tier, we have to start tier rebalance process.
This patch is to trigger tier start along with attch-tier.

>Change-Id: I39380f95123f0087a82213ef263f9f33adcc5adc
>BUG: 1214222
>Signed-off-by: Mohammed Rafi KC <rkavunga@redhat.com>
>Reviewed-on: http://review.gluster.org/10363
>Tested-by: Gluster Build System <jenkins@build.gluster.com>
>Reviewed-by: Dan Lambright <dlambrig@redhat.com>

Change-Id: Ia27e97a9dc0772f3f56b991ce4019281ab7bf1b5
BUG: 1219848
Signed-off-by: Mohammed Rafi KC <rkavunga@redhat.com>
Reviewed-on: http://review.gluster.org/10711
Tested-by: Gluster Build System <jenkins@build.gluster.com>
Tested-by: NetBSD Build System
Reviewed-by: Vijay Bellur <vbellur@redhat.com>

        Backport of http://review.gluster.org/#/c/9989/

This implementation is same as the posix_unlink_cbk() where CTR sends
a request during a unlink to send the number of links to the inode
and posix obliges sending it using the unwind xdata dict.
For Trash xlator a unlink is stat + mkdir(if parent is not present)
+ rename. And hence this is handled in trash_unlink_rename_cbk().

Change-Id: I402e83567b88e3c9fe171379693c82937af567f9
BUG: 1218032
Signed-off-by: Jiffin Tony Thottan <jthottan@redhat.com>
Signed-off-by: Joseph Fernandes <josferna@redhat.com>
Signed-off-by: Anoop C S <achiraya@redhat.com>
Reviewed-on: http://review.gluster.org/10513
Reviewed-by: Joseph Fernandes
Tested-by: Gluster Build System <jenkins@build.gluster.com>
Reviewed-by: Dan Lambright <dlambrig@redhat.com>
Reviewed-by: Vijay Bellur <vbellur@redhat.com>