title: Stop UIScrollView scrolling during touch
body: <p>Is there a way to stop a <code>UIScrollView</code> from scrolling <strong><em>while a touch is still held down</em></strong>? Setting the content offset using the <code>scrollViewDidScroll:</code> delegate method is excessive and can cause some issues (view moves and resets quickly) with the GPU, so I was hoping for a cleaner solution, if there is one.</p>