title: Handling UIContentSizeCategoryDidChangeNotification for NSAttributedString in UITextView
body: <p>I have an NSAttributedString in a UITextView and would like to handle the UIContentSizeCategoryDidChangeNotification when working with Dynamic Type and specifically the text styles. All the examples I've seen (IntroToTextKitDemo) address the case where the font is the same for the whole UI element. Does anyone know how to handle this properly so all the attributes update properly?</p>
  
  <p><em>Note: I asked this on the developer forums when iOS 7 was under NDA. I'm posting it here because I found a solution and thought others might find it useful.</em></p>