[data processing] Plugins page refactoring

[Tatiana Ovchinnikova]

There is no need of 'project/data_processing.data_plugins/_versions_list.html' template to make a list of versions at the plugins table. Using standard Column class attributes is much simpler.

[OpenStack Infra (hudson-openstack)]

Fix proposed to branch: master
Review: https://review.openstack.org/114199

[OpenStack Infra (hudson-openstack)]

Reviewed: https://review.openstack.org/114199
Committed: https://git.openstack.org/cgit/openstack/horizon/commit/?id=604fd47f97c1a5ed2fc0a72a0d3be346a6b96695
Submitter: Jenkins
Branch: master

commit 604fd47f97c1a5ed2fc0a72a0d3be346a6b96695
Author: Tatiana Ovchinnikova <email address hidden>
Date: Thu Aug 14 15:05:08 2014 +0400

    Remove redundant template from data_processing/data_plugins

    Remove 'project/data_processing.data_plugins/_versions_list.html' template
    and make a list of versions at the plugins table using standard Column
    class attributes.

    Closes-Bug: #1356821

    Change-Id: I8121bb658f9799f6cfa7738cdbb5cfa9bbf39cfe