Remove deprecated commands from help

[Dean Troyer]

https://review.openstack.org/#/c/142318/ renamed `os project usage list` to `os usage list`, we need to get `os project usage list` out of the help output before the next release to start its deprecation clock.

This may require a tweak to cliff or a nasty hack into argparse itself...

[Steve Martinelli (stevemar)]

Alternatively, we could issue a deprecation warning for 'os project usage list', telling the user to use 'os usage list'. Keep that around for a release cycle, then remove 'os project usage list'.

[Steve Martinelli (stevemar)]

Also, we may need to do this for 'os user role list' but that'll be tricky since it's used in devstack too

[Dean Troyer (dtroyer)]

Auto-update didn't happen... the prototype of this is being worked in https://review.openstack.org/147379. There are a couple of cliff reviews that will help too: https://review.openstack.org/147349 and https://review.openstack.org/147381

[OpenStack Infra (hudson-openstack)]

Reviewed: https://review.openstack.org/147379
Committed: https://git.openstack.org/cgit/openstack/python-openstackclient/commit/?id=bc11c4d7d8fef1d8eef3bb8f5fa18e27b9ea2964
Submitter: Jenkins
Branch: master

commit bc11c4d7d8fef1d8eef3bb8f5fa18e27b9ea2964
Author: Dean Troyer <email address hidden>
Date: Wed Jan 14 18:44:10 2015 -0600

    Deprecate project usage list command

    Rather than pointing the 'project usage list' entry point directly to
    ListUsage, this makes a ListProjectUsage subclass to alias the desired
    command and still allow for changing behaviour or issuing a deprecation
    messages. This implementation simply sets a new 'deprecated' attribute
    in the command class that cliff will use to skip this command when
    generating help output.

    The actual skipping of the command in help output is dependant on
    https://review.openstack.org/147349 merging in cliff, this review will
    simply have no effect on help output until a version of cliff with
    that update is present.

    The deprecation message printed is somewhat generic until
    https://review.openstack.org/147381 is merged in cliff.
    Until that is merged, the deprecation message will not have the name
    of the actual command given by the user in it, but rather the text
    'this command'.

    Closes-bug: #1406654
    Change-Id: Ie08d4f88d71a660fca1862405351109cd0aa86b6