This patch covers next topics:
1) Changes db deploymnet model to store admin endpoint and list of
non-admin users
2) Changes objects.deployment to have this admin and users instead of
endpoints
3) Changes input format of ExistingCloud engine, to make it easy to
pass users & admins
4) Changes engine.bind method to accept admin and list of users
5) Code cleanup related to removing list of endpoints and making
admin/non-admin stuff
6) Fix CLI code related to deployment model change
7) Fix docs & samples
8) Fixing all related tests
In next patch we should drop default "users" context and use users
from deployment if they are passed.
Change-Id: Ifb469d80c61ee5f26f313db75c98a6d496bcdb92
296558a05e