title: Add the "Select All" option after long tapping a UITextView
body: <p>When I long tap any text in the standard Mail app, I am presented with a "Select All" option.</p>
  
  <p><img src="https://i.stack.imgur.com/krM3K.png" alt="enter image description here"></p>
  
  <p>However, when I long tap text in my own <a href="https://developer.apple.com/library/ios/documentation/UIKit/Reference/UITextView_Class/index.html" rel="nofollow noreferrer">UITextView</a>, I do not get that option. How do I add it?</p>
  
  <p><img src="https://i.stack.imgur.com/Y1lQK.png" alt="enter image description here"></p>
  
  <p>Here is the relevant code for my UITextView is set up:</p>
  
  <pre><code>self.messageLabel = [[UITextView alloc] init];
  self.messageLabel.dataDetectorTypes = UIDataDetectorTypeAll;
  self.messageLabel.editable = NO;
  self.messageLabel.scrollEnabled = NO;
  self.messageLabel.selectable = YES;
  self.messageLabel.textContainerInset = UIEdgeInsetsZero;
  self.messageLabel.textContainer.lineFragmentPadding = 0.0;
  </code></pre>