Add preference and method to disable scrolling independent of KeyboardShrinksView

[kuya1284]

Could you please add the ability to disable scrolling, independent of the KeyboardShrinksView preference? I see that you have an option to disable scrolling when the virtual keyboard shrinks the view. However, I need a way to disable scrolling all together similar to how the Ionic Keyboard plugin handles this. The reason why is because I use the Dojo toolkit, which has modules for rendering scrollable panes and views. Since your shrinkViewKeyboardWillChangeFrame() method forces self.webView.scrollView.scrollEnabled to YES, a conflict occurs.

Giving developers the ability to disable scrolling will give us more flexibility and the ability to controll scrolling via JavaScript.