title: Prepopuilate the current date time in yii2-datecontrol extension
body: <p>I am working in a <code>yii2-grid - GridView</code> <code>kartik\datecontrol\DateControl</code> </p>
  
  <p>I have used <code>DateControl</code> to select the current date-time.</p>
  
  <p>Below is the code where I am trying to view default DateTime in the input.
  But no value gets visible in the input box.</p>
  
  <pre><code>&lt;?PHP 
      $form-&gt;field($model,'last_date')-&gt;widget(DateControl::classname(), [
          type'=&gt;DateControl::FORMAT_DATETIME,
          pluginOptions' =&gt;[
              defaultDate' =&gt; date('dd-MM-yyyy hh:mm:ss a')
          ]                        
      ]);
  ?&gt;
  </code></pre>
  
  <p>I have tried </p>
  
  <pre><code>date('d-m-Y h:i:s A')
  </code></pre>
  
  <p>also but it still displays the empty input box.</p>
  
  <p>Also, try to give the model value to this attribute</p>
  
  <pre><code>$model-&gt;last_date = date('dd-MM-yyyy hh:mm:ss a');
  </code></pre>
  
  <p>but this doesn't affect the input and input show empty.</p>
  
  <p>so help me to get the default date-time display in the input box.</p>