Utility helpers like helpful should not finalize itselves

[qfox]

It's a major change but it will add a way to extend basic behaviour of helpers.

E.g. .helpful().title('another title').act(function() { doSomething(); return this.__base.apply(); }).end().

As temporary (or persistent) alternative we can add an option like .helpful({ endless: true }).

[qfox]

Closed in favor of #82