glusterd: Allow setting volume options by default based on op-version

A new function glusterd_enable_default_options is introduced, which will
set some volume options on a volume based on op-version. This function
is called near the end of the volume create and will allow some options
to be enabled based on op-version on newly created volumes. This will
also be called during volume reset, to reset the options to their
default values if they had changed.

Change-Id: I91057d9e42409b17a884728b43ae3721328d4831
BUG: 1096616
Signed-off-by: Kaushal M <kaushal@redhat.com>
Reviewed-on: http://review.gluster.org/7734
Tested-by: Gluster Build System <jenkins@build.gluster.com>
Reviewed-by: Atin Mukherjee <amukherj@redhat.com>
Reviewed-by: Krishnan Parthasarathi <kparthas@redhat.com>
Tested-by: Krishnan Parthasarathi <kparthas@redhat.com>