* UUIInteractionHandler still needs to implement XInitialization.

* Moved ambiguating InteractionHandler typedef out of the way.

* Removed InteractionHandler.createDefault, as it was originally stated that "it
  is strongly recommended that [the "Parent"] property is supplied."

* Added back documentation about Parent and Context.

* Simplified some call-sites to directly use XInteractionHandler2.

Change-Id: I1029b8f3cf079171c75920cafaaa44b5bbada883