Bugfix - Lifecycleobserver and RxHandler*

[StefMa]

Given: : 🌮
Our sample is broken.
It through a IllegalStateException: view subscriptions can't be handled when there is no view.
This cames from RxTiPresenterSubscriptionHandler.manageViewSubscription which is called from the HelloWorldPresenter#onAttachView(view)

But: Why it says that there isn't any view, when onAttachView is called? 🤔

Reson: ❌
After a quick reseach the reason is simple:
We introduced such a exception with #58 .
So this is working like expected.
But: Why is is thrown on onAttachView?
Because of the TiLifecycleObserver. The documentation says:

/**
* gets called when the {@link net.grandcentrix.thirtyinch.TiPresenter.State} changes
*
* @param state the new state of the {@link TiPresenter}
* @param beforeLifecycleEvent {@code true} when called before the {@code on...} lifecycle
* methods, {@code false} when called after
*/

beforeLifecycleEvent is wrong here.
If we take a look into the implementation in TiPresenter#attachView we see the following:

moveToState(State.VIEW_ATTACHED, false);
// Stuff
onAttachView(view);
// More stuff
moveToState(State.VIEW_ATTACHED, true);

The second parameter here indicates if the on* method is already called.
Which is wrong according to the documentation of the TiLifecycleObserver.

The fix: 💚
Because we have already implementations with the TiLifecycleObserver I've just changed the documentation (and a better boolean name 😉)

I've also fixed the implementation of the RxTiPresenter*Handler.. which have thrown the exception...