title: remove notify callback from chain of Q promise
body: <p>how can I remove the notify callback of a promise? Assume the following jsfiddle</p>
  
  <pre><code>http://jsfiddle.net/anand_anand84/n6syLacs/2/
  </code></pre>
  
  <p>What should be done if I want to remove the stepC from promise1 callback list such that the <code>console.log("HEADER Received =", data);</code> is not printed. </p>
  
  <pre><code>var i = 0;
  var deferred = Q.defer();
  
  var simualteQuotes = function () {
      deferred.notify(i++);
      return "ret 1"
  };
  
  var getQuote = function(scrip){
      //Contains a map containing promises and corresponding scrips;
      //returns the promise of the scrip
     return deferred.promise;
  }
  var stepA = function (data) {
      console.log("Chart Received =", data);
  };
  var stepB = function (data) {
      console.log("MarketWatch Received =", data);
  };
  var stepC = function (data) {
      console.log("HEADER Received =", data);
  };
  
  
  // then() can be used multiple times. It's like, for each then(), a callback is registered.
  // and when the promise is fulfilled, all the registered callbacks are called
  
  var promise1 = deferred.promise;
  var promiseA = promise1.progress(stepA);
  var promiseB = promise1.progress(stepB);
  var promiseC = promise1.progress(stepC);
  
  setInterval(simualteQuotes, 6000);
  </code></pre>