Update glance.openstack.common.policy and cleanup

1. Sync glance.openstack.common.policy up to latest
version from oslo-inc.

2. Clean useless modules which depended by policy
module and pinned gettextutils module there. For
latter one, we are going to use glance.i18n instead.
 * jsonutils
 * strutils

docImpact

Closes-bug: #1288178
Closes-bug: #1387973
Partial-bug: #1381870
Change-Id: I84511ab1ee600e618985448dfbfbdc26cb130370
Signed-off-by: Zhi Yan Liu <zhiyanl@cn.ibm.com>
Merge "Update glance.openstack.common.policy and cleanup"