CLI support for message CRUD operations

This patch extends the queues operation supported by the CLI.

Features added:
- List the messages
- Post a message
- Get one or set of messages
- Delete one or set of  messages

Some examples:
    $ openstack message list --queue_name test_queue
    $ openstack message post --queue_name test_queue --ttl 3600 \
        --body '{"name":"user1", "password":"pass"}'
    $ openstack message get --queue_name test_queue 7778899
    $ openstack message get-set --queue_name test_queue \
        778899 889900 990011
    $ openstack message delete --queue_name test_queue 779900
    $ openstack message delete-set --queue_name test_queue \
        778899 889900 990011

Change-Id: I5ebd153f32704e616fa78d388bf3d50f36c287fa
Partially-Implements: blueprint cli
CLI support for claim CRUD operations

This patch extends the queues operation supported by the CLI.

Features added:
- Create claim
- Query claim
- Update claim
- Release claim

Some examples:
    $ openstack claim create --queue_name test_queue --ttl 3600 \
        --grace 120
    $ openstack claim query --queue_name test_queue 7788990
    $ openstack claim update --queue_name test_queue --ttl 720 \
        7788990
    $ openstack claim release --queue_name test_queue 7788990

Change-Id: I610b1b236376e6be19014717dbe926d8a749198d
Partially-Implements: blueprint cli
code refactor

Change-Id: Ib60f0e42f0640d84564255fe7508c669a78720f5