title: Execute 5 ajax calls at once from a total of n calls
body: <p>I currently have an array of ids I get from an initial ajax call where I need to make subsequent calls.  Let's say there are 20 ids in that array.</p>
  
  <p>What I need to do now is to make 5 calls at once only since we don't want to overload our server.  And once those 5 are complete, start the next 5.  Once its all done I need to console.log('done');</p>
  
  <pre><code>var ids = [3,5,2,6,7,13,35,27,8,5,3,5,26,57,18,3,42,67];
  var results = {};
  
  var ajaxCall = function(id) {
      $.ajax({ 
         url: '/url?id=' + id, method: 'GET'})
        .complete(function(data) {
             results[id] = data;
        });
  }
  </code></pre>