Action interface changes.
First implementation of new controller design.
Split up controllers in interface and implementation.
Removed messaging system (for now).
Some renaming.
Implemented basic proxy functionality. Untested.
Bugfix: Controller actions not working with composite.

When using Controller actions (virtual inheritance), the add_actions()
method failed because the derived actions was not casted to an action
pointer before causing (probably) UB. Changing the add_actions() method
to accept an array instead fixed the problem.
Forgot this...
Basic service interface implemented.
Updated examples.
Merge branch 'controller'