Fixes bug 853933
Add new --username|--password|--tenant|--auth_url|--auth_strategy
switches to bin/glance to allow the username, password, tenant name,
and authentication URL & strategy be specified on the command line.
Avoid needlessly falling back to keystone v2 auth after a successful:
GET /v1.0/tokens
returns with the X-Image-Management-Url or X-Glance header set,
as opposed to X-Server-Management-Url.
Extend the keystone functional test support to ensure that the URL
returned by keystone via the X-*-Url header contains the appropriate
dynamically allocated port for the glance API service.
Ensure the underlying $OS_* environment variables do not leak into the
TestPrivateImagesCli functional tests, also explicitly exercise both
noauth and keystone strategies.
Change-Id: Iee8bf3745d65a9c57a9da803d5cf9ae5f343a159
6cac288a87