NSX: Fix pagination support

Add pagination support to the base plugin,
leaving the service plugin unaltered.

Minor tweaks to the UT where required to
avoid intermittent failures caused by random
ordering.

Closes-bug: 1295854

Change-Id: I03e9e104967716046909d6120426e879f714a5c8
Enable hacking H301 check

This commit enables the H301 hacking rule by removing all the
multiple imports in a single line from neutron.

Partial-Bug: #1291032

Change-Id: I7ba7f82fb36a433d73190eb3d568b6961ccb57c6
Fixing Arista CLI command

A minor change is made to the Arista API between ML2 Driver and the
back-end. This fix addresses this change to align Icehouse release with
Arista EOS releases.

Change-Id: Ia7cd3701c76d920a7e0d1334290c73ce7e8e5576
Closes-Bug: 1301093
Revert changes removing OVSBridge return

This reverts changes from this review [1] which incorrectly removed
the return of the OVSBridge object when calling BaseOVS.add_bridge.
This broke all functional tests relying on this return.

[1] https://review.openstack.org/#/c/71142/

Related-Bug: #1301363

Change-Id: If32e155cc2bd368b2e842f14b1d1da0827ccfeff
update doc string - correct typo

Change-Id: I70503293cdd17a520dd9ec66ee297f2d36added6
Merge "NSX: Fix pagination support"
Merge "update doc string - correct typo"
Merge "Fixing Arista CLI command"
Merge "Enable hacking H301 check"
Merge "Revert changes removing OVSBridge return"