title: How to assign custom css class to upload button in fineuploader?
body: <p>I have below code to initialize the fineuploader. i want to assign my custom class to upload button. I tried 
    mentioning  subelement button: 'my-custom-class' under classes element(as shown below) but issue is button is not displayed.
    i am not sure what i am missing here?</p>
  
  <pre><code>$("#my-file-uploader").fineUploader({
  request: {
          endpoint: 'my endPoint'
      }
  classes: {
     success: 'alert alert-success',
     fail: 'alert alert-error',
     button: 'my-custom-class'
  }
  </code></pre>
  
  <p>});</p>
  
  <p><strong>Update:-</strong></p>
  
  <p>I also tried but then button click does not work</p>
  
  <pre><code>$("#my-file-uploader").fineUploader({
  request: {
          endpoint: 'my endPoint'
      }
   classes: {
     success: 'alert alert-success',
     fail: 'alert alert-error',
    button: 'my-custom-class''
  },
  template: '&lt;div class="qq-uploader"&gt;' +
   '&lt;div class="my-custom-class'"&gt;&lt;div&gt;my upload&lt;/div&gt;&lt;/div&gt;'  +
  '&lt;span class="qq-drop-processing"&gt;&lt;span&gt;{dropProcessingText}&lt;/span&gt;&lt;span class="qq-drop-processing-spinner"&gt;&lt;/span&gt;&lt;/span&gt;' +
  '&lt;ul class="qq-upload-list"&gt;&lt;/ul&gt;' +
  '&lt;/div&gt;'
  </code></pre>
  
  <p><strong>Update 2:-</strong></p>
  
  <p>I tried approach 1 as suggested by Ray in first answer it works. But i see two issues here:-</p>
  
  <p><strong>Issue 1:-</strong> if i use any predefined jquery ui class for upload button like ui-button , it does not work.Though it works with any other custom class.</p>
  
  <p><strong>Issue 2:-</strong>  If i need to use use multiple custom class for upload button, say button: <code>'my-custom-class1  my-custom-class2'</code>. Is it achievable? If yes how will i initialize the fineUploader in that case?</p>
  
  <pre><code>   $("#my-fine-uploader").fineUploader({
      button: $(".my-custom-class1 .my-custom-class2")
  });
  </code></pre>