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.
The ActionProvider can handle _everything_ on its own. So why should it bother an activity with events or with new methods to be implemented? Encapsulation rules most other design patterns, in my opinion at least.