Multiple improvements & fixes

* Custom scroll view uses setBounds and setFrames instead of layoutSubviews to allow content to animate along with the external frame (instead of jumping right to the final position while the frame animates)
* Exposes custom scroll view
* Exposes movie player controller
* Adds content type readable property to allow subclasses to adapt content-aware behavior
* Expose image content adjustment (scale to fit) methods to allow for arbitrary adjustment to the viewport