title: I have an issue with initializing Jquery File upload plugin
body: <p>I'm using this plugin for my upload in backbone, however, I have to submit 2 times before uploading.
  When I chose my file for the first time it seems like the fileupload function doesnt execute, and then when I chose a second time it will execute.</p>
  
  <p>It seems like very stupid but I don't get where i'm wrong..</p>
  
  <p>Here's the backbone part:</p>
  
  <pre><code>form_submit: function(e){
  
      $('#fileupload').fileupload({
      add: function (e, data) {
  
  
          // Automatically upload the file once it is added to the queue
          var jqXHR = data.submit();
      },
      progress: function(e, data){
          var progress = parseInt(data.loaded / data.total * 100, 10);
          $('#progress .progress-bar').css(
          'width',
          progress + '%'
          );
          if (progress == 100) {
          var message = "&lt;font color=green&gt;Fichier uploadé !&lt;/font&gt;";
          var info = document.getElementById("info");
          info.innerHTML=message;
          }
      }
      });
  }
  </code></pre>
  
  <p>and here's my html part if it can helps:</p>
  
  <pre><code>&lt;form enctype="multipart/form-data" id="maj-container"&gt;
      &lt;script type="text/template" id="maj-template"&gt;
        &lt;div class="file-input-wrapper" id="file-group"&gt;
      &lt;button class="btn-file-input" id="btn-file"&gt;Choisir un fichier&lt;/button&gt;
      &lt;input type="file" name="files[]" id="fileupload" multiple /&gt;
        &lt;/div&gt;
        &lt;br&gt;
        &lt;br&gt;
        &lt;div id="progress" class="progress"&gt;
      &lt;div class="progress-bar progress-bar-success"&gt;&lt;/div&gt;
        &lt;/div&gt;
        &lt;div id="info" style="margin-top:30px"&gt;&lt;/div&gt;
      &lt;/script&gt;
    &lt;/form&gt;
  </code></pre>
  
  <p>EDIT: 
  Ok so I made some research and apparently this error occurs because I don't initialize the plugin.
  So I tried to initialize it by doing $('#fileupload').fileupload(); but It doesn't work.
  I tried to place it in differents places: at the beginning of the form_submit function, in the render:</p>
  
  <pre><code>render: function(){
      var template = _.template(this.template.html());
      this.$el.html(template({ m : this.model.toJSON()}));
      $('#fileupload').fileupload({
      url: '/rest/maj/',
      sequentialUploads: true
      });
      return this;
  },
  </code></pre>
  
  <p>I tried also in the initialize:</p>
  
  <pre><code>initialize : function(options) {
  
          $('#fileupload').fileupload({
      url: '/rest/maj/',
      sequentialUploads: true
      });
      this.router = options.router;
      this.render();
  
  
  },
  </code></pre>
  
  <p>But nothing works.. it still doesn't fire at first time.</p>