add logic operator to Authorization

add logic operator to be easly to reuse authorization.

```scala
case class WithProvider(provider: String) extends Authorization[User] {
  def isAuthorized(user: User)(implicit request: RequestHeader, lang: Lang) = {
    user.identityId.providerId == provider
  }
}
```

```scala
def myAction = SecuredAction(WithProvider("twitter") || WithProvider("facebook")) { implicit request =>
  // do something here
}

def myAction = SecuredAction(!WithProvider("twitter")) { implicit request =>
  // do something here
}

def myAction = SecuredAction(WithProvider("twitter") && WithProvider("facebook")) { implicit request =>
  // do something here
}
```
Please could you add the DocBlock for the object and the methods.