(QE-725) Minor bugfix and documentation addition.

* Document `ezbake_stage` method.
* Fix directory creation bug in `conditionally_clone` method.

Signed-off-by: Wayne <wayne@puppetlabs.com>
Merge branches 'feature/create-tmpdir-for-user-on', 'feature/curl-retries', 'feature/ezbake-utils' and 'feature/logging-improvements' into merged