Adding support for decommissioning

The pluggable hardware manager should be able be used for decommissioning,
such as erasing disks, updating firmwares, changing BIOS settings, and
anything else specific hardware needs. This works with the agent driver
to store state in Ironic and request out of band reboots (which may be
required to make BIOS/firmware updates work). Also allows the agent to do
some basic verification of the node's properties, to ensure they haven't
changed, such as a stick of memory dying.

Change-Id: Ia42a8e75d2b8887b2351de97c2137fe21a7f4041
(cherry picked from commit e2444f06ea80d2ee1391272504399177f2c52a7d)
Add versioning to Agent decommission

As the agent will likely be rebooting while decommissioning (to apply BIOS/
firmware upgrades), it is possible the version of the agent will change
between boots. Including a version string in the Hardware Manager allows
the Hardware Manager builder to bump versions for any breaking changes.
I recommend that the entire decommission process be restarted if there
is a version mismatch, but that will be up to individual drivers to
implement.

This change also adds a new return value for Agent REST commands called
'DECOM_VERSION_MISMATCH' that will signal no command was run, and
Ironic should update its stored value. A 'hardware_manager_version'
will be returned with AsyncCommandResult, and should be set in the
Ironic driver_info field and sent with any decommission command.

Change-Id: I2ae0e93573e0348f023aa124a07bb16921b5c53e
(cherry picked from commit e0f726e446d878f69862fc1c5aaf72dc6111324a)
Use LLDP to get switch port mapping

Provides a function to listen for LLDP packets on the network.
Listens on one or all of the network interfaces, and then parses the found
packets.

Change-Id: I1545a41f46cd0916aab9c43ce036865454fa66e0
Co-Authored-By: Josh Gachnang <josh@pcsforeducation.com>
(cherry picked from commit 81a36dd7088984823ba9ae77799196eb3bd19ed4)