New redirect strategy

I change the way the redirect strategy works.
The redirects from authenticate/logout actions are now callbacks.
This way the user can overwrite the default callback and decide **exactly** what to should happen.

ping @Ocramius

closes #479
closes #476
closes #473
closes #469
@Ocramius set the request/response like this or set $this->application and then get the request/response in the methods through $this->application?