title: Using SELECT2 4.0.0 with infinite Data and filter
body: <p>I'm using Select2 now since 2 years and I really enjoy all dev made. however, version 3.5.x has his limit, so I'm moving to version 4.0, which give me headaches!</p>
  
  <p>For your record, I'm using Select2 with large table (> 10.000 entries), so AJAX &amp; infinite data (page set to 50 items). </p>
  
  <ol>
  <li><p>With version 3.5.2, I can reproduce the underline match when searching for data (using <code>formatSelection</code> and <code>query.term</code>). Any idea how to make it with version 4.0.0 (function <code>templateResult</code> only passes <code>result</code> and not <code>query</code> anymore?</p></li>
  <li><p>With version 3.x, you can add free entries using search value was not in the list (using <code>createSearchChoice</code>). Version 4.0 does not have this option, any idea how to make it again?</p></li>
  <li><p>I try to replace the Select bar with an input bar (still using the select dropdown). It seems possible to force the adapter but I was unable to find how.</p></li>
  <li><p>I need to add either a line (at row 1) or a button (floating to the right) to add new item (similar to <code>createTag</code>, but for an item). has someone made it already?</p></li>
  </ol>