Observable.swift

    let _name = Observable<String>("Hello")
    var name: ObservableOf<String> {
        return ObservableOf(self._name)
    }
    
    var scope: NSString? = "Yeehaw"
    self.name.observe { (oldValue, newValue) -> Void in
        print("\(oldValue) => \(newValue)")
    }.scopeTo(scope!)
    self._name.value = "Payne"
    scope = nil
    self._name.value = "Scope was deallocd so this wont be called"