* move auth option checking back to OpenStackShell() to keep the shell-level
interaction at that level; add checking for token flow options
* make identity.client.make_client() configure keystoneclient.v2_0.Client()
properly for both password flow and token flow auth
* eliminated ClientManager.init_token(), set _service_catalog in __init__()
* compute client handles token flow
Change-Id: I42481b5424489387798c4ec6d3e2a723ab1e6067
6fb1a4e496