If this option is "ON' and if there is a lock contention for
a file from 2 clients/self-heal daemon, an up call will
be sent to all the clients holding that locks. Clients
can handle this notification and may release the locks
at the right time asap.

If this option is ON, we get "instant" lock contention
notification on client side.

In next version of thin arbiter,  we need to implement
lock contention notification handling and two domain
locking to synchronize update/access of xattrs of thin arbiter
replica id file. This option is an efficient way to find
out lock contention. In this case it is also helping to
implement two domain locking for replica id file.

Change-Id: I69883898d52feb425dfceb31cf12fa2157aaa314
fixes bz#1609207
Signed-off-by: Ashish Pandey <aspandey@redhat.com>

1 - setup-thin-arbiter.sh
To setup directory path for thin-arbiter. This is the path where replica id
file will be placed and used by TA process.
By default it will be /mnt/thin-arbiter. It is better to use default path
and once set it should not be changed.

2 - gluster-ta-volume.service
This is the Unit file used by systemd to start and keep the thin-arbiter
process running.

3 - thin-arbiter.vol
This is the default volume file for thin-arbiter. It will be used to start
thin-arbiter process. This should not be modified by user except the
directory path which can be modified using [1].

Change-Id: I68f2164f24adfa326c1d1a7a98c6ac4ff04ed553
fixes: bz#1579786
Signed-off-by: Ashish Pandey <aspandey@redhat.com>