title: Search unique value with DataTable search()
body: <p>I have a table. In that table there is a <code>status</code> column which contains text <code>active</code>, <code>inactive</code> and <code>warning</code>. I have made a filter for the <code>status</code> column, but the problem is when the filter is <code>active</code> then the <code>inactive</code> rows are also shown.</p>
  
  <p>How do I make it so that if the user selects <code>active</code>, <code>inactive</code> is not shown?</p>
  
  <pre class="lang-html prettyprint-override"><code>&lt;select name="status" id="status" class="form-control"&gt;
    &lt;option value=""&gt;Select Status&lt;/option&gt;
    &lt;option value="active"&gt;active&lt;/option&gt;
    &lt;option value="inactive"&gt;inactive&lt;/option&gt;
    &lt;option value="warning"&gt;warning&lt;/option&gt;
  &lt;/select&gt;
  </code></pre>
  
  <pre class="lang-js prettyprint-override"><code>$("#status", this).on("click", function() {
    if (SomeTable.column(4).search() !== this.value) {
      SomeTable
        .column(4)
        .unique()
        .search(this.value)
        .draw();
    }
  });
  </code></pre>