toro: Playback inconsistencies

Hi,

Thanks for the great library. I have been trying to implement this on a recommendation from a different library (FastAdapter), but I have noticed a couple of issues. I can post these a separate issues if required.

1. Playback off screen with a ViewPager - I have managed to combat that before with setUserVisibleHint from the Fragment. Although I am not sure how you would do this with your implementation yet
2. Playback off screen whilst scrolling - If you scroll the play video off the screen, but then scroll very slightly whilst keeping it off the visible screen you can still hear the video playing even though it isn’t visible. It seems like the visibility calculator isn’t catching it for some reason. Either that or one of the next videos isn’t switching from its Prepared state
3. Looping - I notice you have this kind of setup in the Toro strategies. When will this become available? I want to loop the videos continuously, but know when they have stopped before they loop again. Or should this be done when onPlaybackStopped is called, but you don’t have access to a MediaPlayer, so I’m not sure how to loop back around.

All of these points I can replicate in the supplied demo application. I am using very short content ≈8 seconds long, with sounds. Hence why I noticed some of these issues.

I am testing this on an Nexus 5 running Android 5.0 using Toro 1.1.0.