This fixes issues with other React Native views which rely on the view controller hierarchy.

* Move logic for tap background to dismiss out of background color view

This allows for tapping the background without setting a color here, meaning this feature can be enabled with one less view in the view hierarchy

* Only allow taps on views that aren't the React view

This allows for taps on any background view, visual effect view, color tint view, etc, but not on the content.

* Added tapBackgroundToDismiss to LightBox screens

* Updated LightBox readme

* Formatting updates

* Fixed ios selector

* Updated animationEnd hide method

fixes #800 #797