unnecessary L3 rpcs

[YAMAMOTO Takashi]

networking-midonet plugin currently issues RPCs for L3-agent unnecessarily.
they are unnecessary as the plugin doesn't use neutron L3-agent at all.
many (not all) of these RPCs are a consequence of using L3_NAT_db_mixin as a base class. the plugin should use L3_NAT_dbonly_mixin instead.

in order to do that, a few RPC assumptions in neutron needs to be fixed.
namely,
- ML2 uses disassociate_floatingips(do_notify), which is only available in L3_NAT_db_mixin
- a few l3 tests unnecessarily assume L3_NAT_db_mixin

[OpenStack Infra (hudson-openstack)]

Fix proposed to branch: master
Review: https://review.openstack.org/257467

[OpenStack Infra (hudson-openstack)]

Fix proposed to branch: master
Review: https://review.openstack.org/257468

[Carl Baldwin (carl-baldwin)]

The description here is lacking detail. Please detail the RPC message which are unnecessary and the RCP assumptions being made.

[YAMAMOTO Takashi (yamamoto)]

Carl, i updated the description with some details.

[OpenStack Infra (hudson-openstack)]

Change abandoned by Armando Migliaccio (<email address hidden>) on branch: master
Review: https://review.openstack.org/257467
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)]

ping?

[OpenStack Infra (hudson-openstack)]

Change abandoned by Armando Migliaccio (<email address hidden>) on branch: master
Review: https://review.openstack.org/257468
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.

[OpenStack Infra (hudson-openstack)]

Change abandoned by Armando Migliaccio (<email address hidden>) on branch: master
Review: https://review.openstack.org/257375
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.