title: Select2 dropdown doesn't close on click
body: <p>I'm using <a href="https://select2.github.io/" rel="noreferrer">Select2 (v4)</a> in a multiple select form and having difficulty getting the dropdown close functionality I need. I have <code>closeOnSelect</code> set to <code>false</code>, so the user can add multiple values easily. What I'm seeing on a test site is that on all browsers except iOS, when you click outside of the dropdown area, the dropdown closes (which is the desired behavior). On iOS, the only way to get it to close is to click inside the input.</p>
  
  <p>Oddly enough, in trying to replicate via jsfiddle, I can only get version 4 of Select2 to behave the way I'm seeing it on iOS - <a href="http://jsfiddle.net/8g27t277/" rel="noreferrer">http://jsfiddle.net/8g27t277/</a></p>
  
  <p>I have another jsfiddle using Select2 v3.4.6 which shows the click-to-close functionality I want across all browsers - <a href="http://jsfiddle.net/0tefq3yz/" rel="noreferrer">http://jsfiddle.net/0tefq3yz/</a></p>
  
  <p>Test HTML:</p>
  
  <pre><code>&lt;select id="options" size="9"&gt;
      &lt;option value="357"&gt;One&lt;/option&gt;
      &lt;option value="358"&gt;Two&lt;/option&gt;
      &lt;option value="359"&gt;Three&lt;/option&gt;
      &lt;option value="360"&gt;Four&lt;/option&gt;
      &lt;option value="361"&gt;Five&lt;/option&gt;
  &lt;/select&gt;
  </code></pre>
  
  <p>Test js:</p>
  
  <pre><code>$('#options').select2({
      "placeholder": "Pick multiple options",
      "multiple": true,
      "closeOnSelect": false
  });
  </code></pre>
  
  <p>What's causing the dropdown to close (or not) in response to click events outside the input?</p>