support name and id in role,user,tenant query

If you create a role/user/tenant with a name that already exists, it will return a HTTP 409
e.g. Conflict occurred attempting to store user.
The name has uniqueness. This means that you can query a role/user/tenant with its name.

In python-keystoneclient support the name input query, it just find the item form the list if the name is in it.

python-keystoneclient user-get code:
@utils.arg('user', metavar='<user>', help='Name or ID of user to display.')
def do_user_get(kc, args):
    """Display user details."""
    user = utils.find_resource(kc.users, args.user)
    utils.print_dict(user._info)

The python-keystoneclient (role/user/tenant) resourceManager.get method was never called.

Then test keystone api call directly:

set user_id in the resource url:

curl -i -X GET http://xxxxxxx:35357/v2.0/users/e9f5188d12c043fdbbfec0cfa748d7b8 -H "User-Agent: python-keystoneclient" -H "X-Auth-Token: ba38f0bdd3a74abfaf84dc884ebf5fc6"

HTTP/1.1 200 OK
Vary: X-Auth-Token
Content-Type: application/json
Content-Length: 138
Date: Wed, 07 Jan 2015 03:15:51 GMT

{"user": {"username": "admin", "name": "admin", "enabled": true, "email": "<email address hidden>", "id": "e9f5188d12c043fdbbfec0cfa748d7b8"}}

set username in the resource url:
curl -i -X GET http://xxxxxxx:35357/v2.0/users/admin -H "User-Agent: python-keystoneclient" -H "X-Auth-Token: ba38f0bdd3a74abfaf84dc884ebf5fc6"

HTTP/1.1 404 Not Found
Vary: X-Auth-Token
Content-Type: application/json
Content-Length: 88
Date: Wed, 07 Jan 2015 03:16:02 GMT

{"error": {"message": "Could not find user, admin.", "code": 404, "title": "Not Found"}}

V3 api has the same result.