Expand tag length limit to 80

[Zhenyu Zheng]

The tag has a limited length, and in the current implementation, it is 60 in the tag object definition:
http://git.openstack.org/cgit/openstack/nova/tree/nova/objects/tag.py#n18

but 80 in the db model:
http://git.openstack.org/cgit/openstack/nova/tree/nova/db/sqlalchemy/models.py#n1464

We should expand the limitation in tag object definition to 80 as we have already created a 80 long
space in db and this may be confusing. Besides, users can make more use of the longer tags.

[OpenStack Infra (hudson-openstack)]

Fix proposed to branch: master
Review: https://review.openstack.org/421004

[OpenStack Infra (hudson-openstack)]

Change abandoned by Zhenyu Zheng (<email address hidden>) on branch: master
Review: https://review.openstack.org/421004

[Sean Dague (sdague)]

There are no currently open reviews on this bug, changing the status back to the previous state and unassigning. If there are active reviews related to this bug, please include links in comments.