DO NOT MERGE YET: Fixes #3843, Action Bar: Secondary navigation tool?

- added an action provider that handles the long click and redirects to secondary default navigation

This would bring back the functionality as it was before, at the expense of loosing the normal long-press functionality.
Thinking again I am not sure if the ActionProvider shoudl really involve himself with the details of the action to trigger. I see it rather as an event generator than as an actor itself (which IMO is also aligned with the behaviour of the normal action items).
Perhaps I should revisit this to just trigger onOptionItemSelected and carry the state of long-press or not...
Than again I need no interface and no knowledge about the caller at all...