Fix some typos in neutron/db and IBM SDN-VE plugin

For example, in neutron/db/agents_db.py, db_plugin_base_v2 should be changed to db_base_plugin_v2.
There is no bug or blueprint related to this fix.

Change-Id: I0d348d92c9c32f172d1e505cf660aed4d064a440
OFAgent: Avoid processing ports which are not yet ready

Port the following patch to OFAgent.
commit: 2702baed390d094b0eac07d0ae167ed236868d00
https://review.openstack.org/#/c/65838/

Closes-Bug: 1307745

Change-Id: Ie1fe0944fb541ba45ffb5b03747d5da289cede51
OFAgent: Fixing lost vlan ids on interfaces

Port the following patch to OFAgent.
commit: 60cb0911712ad11688b4d09e5c01ac39c49f5aea
https://review.openstack.org/#/c/66375/

Closes-Bug: #1309286

Change-Id: I04f99ef7928cd07959b29eb64b5744df397979b8
Synced jsonutils from oslo-incubator

The sync includes change that makes sure we get unicode-only dicts from
jsonutils no matter which json module implementation is selected.

The latest commit in oslo-incubator:
- 0f4586c0076183c6356eec682c8a593648125abd

The sync adds a new 'strutils' module that is now used in jsonutils.

Change-Id: Ic815ca3df94c33edec9104172048b2cd94b92e3f
Closes-Bug: 1314129
Merge "Fix some typos in neutron/db and IBM SDN-VE plugin"
Merge "Synced jsonutils from oslo-incubator"
Merge "OFAgent: Avoid processing ports which are not yet ready"
Merge "OFAgent: Fixing lost vlan ids on interfaces"