Bring in the new cmd code and fix badly placed function.
Add a log to avoid test failure of 'true != false'
Merge pull request #957 from howbazaar/user-help

Bring in the new cmd code and fix badly placed function.

In order to get the sub-command help usage right, bring in the new juju/cmd revisions.

There was a file removed from juju/cmd that shouldn't have been there, that was used by the addunit command.  This has been moved to be close to the code that uses it.