plugin(core, service) is unnecessarily cached and they are implemented variously by many times

[Isaku Yamahata]

There are patterns like

    @property
    def core_plugin(self):
        try:
            return self._core_plugin
        except AttributeError:
            self._core_plugin = manager.NeutronManager.get_plugin()
            return self._core_plugin

There are issues.
- NeutronManager.get_plugin already cached it. No need to cache again.
- each class implements its own way(with or without cache), various name.

The caching should be removed and their implementation should be unified

[OpenStack Infra (hudson-openstack)]

Fix proposed to branch: master
Review: https://review.openstack.org/131027

[Eugene Nikanorov (enikanorov)]

I'm not sure this worth refactoring

[OpenStack Infra (hudson-openstack)]

Change abandoned by Kyle Mestery (<email address hidden>) on branch: master
Review: https://review.openstack.org/131027
Reason: This review is > 4 weeks without comment, and failed Jenkins the last time it was checked. We are abandoning this for now. Feel free to reactivate the review by pressing the restore button and leaving a 'recheck' comment to get fresh test results.

[Armando Migliaccio (armando-migliaccio)]

This bug is > 172 days without activity. We are unsetting assignee and milestone and setting status to Incomplete in order to allow its expiry in 60 days.

If the bug is still valid, then update the bug status.

[Launchpad Janitor (janitor)]

[Expired for neutron because there has been no activity for 60 days.]