Save the user command text into the command object

[Dean Troyer]

The Command objects do not know what command string the user entered to invoke the Command class. since the user text to class mapping is done in entry points the Command class does not know what invoked it. Sometimes it is useful to know this, especially when multiple command entry points load the same class.

App.run_subclass() pass the command name in the cmd_factory() call.

One use case for this is when subclassing command classes, for example, or to change behaviour through the command name; think of it as symlinking UNIX commands and branching based on the value of $0 or argv[0].

[OpenStack Infra (hudson-openstack)]

Fix proposed to branch: master
Review: https://review.openstack.org/147381

[OpenStack Infra (hudson-openstack)]

Reviewed: https://review.openstack.org/147381
Committed: https://git.openstack.org/cgit/openstack/cliff/commit/?id=91f5ad385b757d2856ee4d2e64f6614e4ad8f7c5
Submitter: Jenkins
Branch: master

commit 91f5ad385b757d2856ee4d2e64f6614e4ad8f7c5
Author: Dean Troyer <email address hidden>
Date: Wed Jan 14 22:50:19 2015 -0600

    Pass user command text to the Command object

    Previously the Command objects did not know what command text was entered
    by the user. That mapping is done in entry points and was thrown away in
    App.run_subcommand().

    This adds cmd_name as an optional keyword arg to Command.__init__() and
    saves it as an attribute. App.run_subcommand() passes in the original
    command text to cmd_factory() and all is well.

    Closes-bug: #1411095
    Change-Id: I36c42b0447652ed3bd71ad6ae0d70db7d27abbad