Makes the existing functional tests run using three
auth modes: tempauth (v1), keystone v2 and keystone v3.
The latter uses an account in a non-default domain
(which exists in devstack setup).

This should help avoid regressions in handling different
auth options.

Change-Id: Ifee6a4fa418242892bf73eda5e2cad7b803b1bee

Adds doc for account_username option to sample test.conf.
This option was added in [1].

[1] change id Ic484e9a0c186c9283c4012c6a2fa77b96b8edf8a

Change-Id: Ic86b274e9d954822da521360981f796d61efaad9

Enables swiftclient to authenticate using
the keystone v3 API, allowing user id's, user
domains and tenant/project domains to be
specified.

Since swiftclient imports keystoneclient, the
main changes in swiftclient/client.py are to
selectively import the correct keystoneclient
library version and pass a number of new
options to it via the get_auth() function. In
addition the get_keystoneclient_2_0 method
has been renamed get_auth_keystone to better
reflect its purpose since it now deals with
both v2 and v3 use cases.

In swiftclient/shell.py the new options are
added to the parser. To make the default help
message shorter, help for all the --os-*
options (including the existing v2 options)
is only displayed when explicitly requested
usng a new --os-help option.

A new set of unit tests is added to
test_shell.py to verify the parser. A comment
in tests/sample.conf explains how to
configure the existing functional tests to
run using keystone v3 API.

Note that to use keystone v3
with swift you will need to set
auth_version = v3.0 in the auth_token
middleware config section of
proxy-server.conf.

Change-Id: Ifda0b3263eb919a8c6a1b204ba0a1215ed6f642f

Coverage for swiftclient.client is 71% with these tests.

Unit tests have been moved into another subdirectory
to separate them from functional tests.

Change-Id: Ib8c4d78f7169cee893f82906f6388a5b06c45602