WebApp documentation and UsageError proof of concept.
More webapp documentation
Scrap UsageError; not worth the pain to extend WebDriver but not build a new driver instance.
Implement waits for displayed (Element) and waits for visible (Container).  Removed superflous NonExistentElement (use selenium's native NoSuchElementException).
Add CheckableElement, Widget, and CheckableWidget constructs.
Implement a common element base and checkbox element.
Re-organized for cleaner python packaging.  Add ElementList.
Yet more re-organization; hopefully this is correct now.  Added TAG strategy.
Add common.unique for getting unique data.
Add common.util and impelement canonical name method.
Add common objects.  General improvements & cleanup.