Enable automatic validation of many HACKING rules.
Enable automatic validation of many HACKING rules.

 * Add hacking to the tox build - a set of flake8 plugins that
   perform automatic validation of many HACKING.rst rules.
 * This patch configures hacking in the tox build and performs
   the mechanical cleanup required to allow the checks to pass.
 * See https://pypi.python.org/pypi/hacking

Change-Id: Ie9b3eb5627a9b6dd181f79225abae422e6cf3777

cisco-openstack/networking-cisco,CiscoSystems/networking-cisco,Tehsmash/networking-cisco-apic,Tehsmash/networking-cisco,openstack/networking-cisco,Gitweijie/first_project,CiscoSystems/networking-cisco,openstack/networking-cisco,hareeshpc/networking-cisco,Tehsmash/networking-cisco,nikolay-fedotov/networking-cisco,Tehsmash/networking-cisco-nexus,noironetworks/networking-cisco,Gitweijie/first_project,noironetworks/networking-cisco,hareeshpc/networking-cisco,cisco-openstack/networking-cisco