code: function doPostBinary(binary, url, successCallback, errorCallback) {
          var xhr = new XMLHttpRequest();
          xhr.open('POST', url);
          xhr.onload = function() {
              if(xhr.status === 200) {
                  successCallback(xhr.response);
              } else {
                  errorCallback(xhr.response);
              }
              hideDefaultSpinner();
          };
          showDefaultSpinner();
          xhr.send(binary);
      }
docs: Asynchronously posts binary data to the specified URL.
  @method doPostBinary
  @param {Blob} binary The binary data to be uploaded.
  @param {String} url The URL to post to.
  @param {Function} successCallback The function to call when the post successfuly completes.
  This function takes the server's response as its parameter.
  @param {Function} errorCallback The function to call when an error occurs. This function
  takes the server's response as its parameter.