This function hides the progress dialog displaying the spinner.
This function should be used to hide the progress dialog after a call to hwc.showProgressDialog. If this function is called while there is no progress dialog, then nothing will happen.
<static> hideProgressDialog()
var showProgress = function()
{
   hwc.showProgressDialog( "a message" );
   setTimeout( hideProgress, 10000 );
}
var hideProgress = function()
{
   hwc.hideProgressDialog();
}