Support packet_filter extension in NEC plugin

blueprint nec-packet-filter-cli

Also adds common validators.

Change-Id: Ia431c2268e9a654e10dc9cf740288fb746825d13
Use requests module for HTTP/HTTPS

This change introduces the use of requests in lieu of httplib2
to ensure proper handling of SSL termination.

Implements: blueprint tls-verify

Change-Id: If182f2addf26421873b8c3d2b60f8cba9b7a9450
Allow user ID for authentication

In Keystone V3 user names are no longer necessarily unique
across domains.

A user can still authenticate a user in the non default
domain via the V2 API providng they use IDs instead of names.

Tenant_ID is already supported, this change adds support
for user ID

Closes-Bug: #1299807

Change-Id: I22fdd9a6749f7dfbdd2dc8313fddc81e5ea0b753
Updated from global requirements

Change-Id: Ic71ae06e070f186ede1bdecd685498fb5a5c3103
Merge "Use requests module for HTTP/HTTPS"
Merge "Allow user ID for authentication"
Remove httplib2 requirement

There are no imports from httplib2 and everything seems to be converted
over to using the requests library now, so remove the extraneous
dependency.

Change-Id: I6a2a9543ea8f5da29494e1dba7659ec02a43deea
Updated from global requirements

Change-Id: Ie4d964feb6111f173338e510ed83d7f1d79f7dbb
Merge "Remove httplib2 requirement"