Bump min required version for dnsmasq to 2.63

This patch bumps the min version requirement from 2.59 to 2.63
for dnsmasq which is needed to use multiple tags for dual stack IPv4/6.

DocImpact

Change-Id: Ib71b8a3a866f5781b57d1589741bcaae594b76db
Closes-bug: 1233339
NSX: remove unnecessary checks on network delete

Since commit b50e66f router interfaces are not deleted
automatically when the network hosting them is deleted.

The NSX plugin still has additional logic to ensure all the
corresponding backend resources have been deleted as well.
Such logic is now obsolete and can be removed. Moreover it
also wasteful as it perform queries for retrieving NSX
resource identifiers.

This patch also amends a few related log statement to make
them clearer.

Change-Id: If3d8d98096a8363b216707f2558e37c80f58e515
Closes-Bug: #1339401
ML2 mechanism driver for SR-IOV capable NIC based switching, Part 1

This set of changes introduces the ML2 mechanism driver for SR-IOV capable NIC based switching.
Please see the blueprint for more information.
The review is submitted in two parts:
- Part 1 (this part)
    The Mechanism Driver to support port binding for SR-IOV virtual functions of
    SRIOV capable switching NICs, such as Mellanox ConnectX Family.

    Use configurable list of supported NIC vendor and product PCI ids to filter
    devices to bind the SR-IOV port.
    Use configurable agent_required option to require SRIOV L2 Agent
    for bort binding.

- Part2
    The SRIOV NIC Based L2 Agent.

Partially implements: blueprint ml2-sriov-nic-switch

Change-Id: If3d28df2a8ffe72ae512ddae076f42fca936cff7
This patch changes the name of directory from mech_arista to arista

This name change of directroy is needed so that additional drivers
can be moved into this directory and share the code among drivers.

In order to accomodate this name change, setup.cfg is modified to
point to the Arista ML2 driver at the new location. Additionally,
a similar new directroy is created for test files as well.

Change-Id: I614ccf8b6d152aa99e20ef1ea762c26115ab9373
closes-bug: 1346712
Merge "ML2 mechanism driver for SR-IOV capable NIC based switching, Part 1"
Merge "Bump min required version for dnsmasq to 2.63"
Merge "This patch changes the name of directory from mech_arista to arista"
Merge "NSX: remove unnecessary checks on network delete"