[doc] [ZFSonLinux] Add 'manage share' feature support

[OpenStack Infra]

https://review.openstack.org/333994
Dear bug triager. This bug was created since a commit was marked with DOCIMPACT.
Your project "openstack/manila" is set up so that we directly report the documentation bugs against it. If this needs changing, the docimpact-group option needs to be added for the project. You can ask the OpenStack infra team (#openstack-infra on freenode) for help if you need to.

commit f284db4e07209b814ea4dcef954490117da50c7f
Author: Valeriy Ponomaryov <email address hidden>
Date: Fri Jun 24 19:17:34 2016 +0300

    [ZFSonLinux] Add 'manage share' feature support

    Implement 'manage share' feature in ZFSonLinux share driver.

    Prerequisites:
    - share being managed should exist.
    - share being managed should not be part of any replication relations.
    - share being managed should not have redefined mountpoint.

    Details:
    - share being managed will be renamed by share driver based on taken ID.
    - share being managed will get "quota" attribute set based on provided
      value in API (--driver_options size=5) or it will set quota
      to nearest bigger rounded integer of already
      used space (2,4 -> 3, 3.6 -> 4).

    Implements blueprint zfsonlinux-manage-share
    DocImpact

    Change-Id: I03eab5e02835fe660dde0020601c02c0136bddeb

[Goutham Pacha Ravi (gouthamr)]

Hi Valeriy,

Anything to add to the devref within manila / configref within openstack-manuals? If not, we can mark this bug invalid.

[Tom Barron (tpb)]

zfs_on_linux_driver.rst and share_back_ends_feature_support_mapping.rst updates were included with the feature in https://review.openstack.org/333994