title: watch on getSelectedRows()
body: <p>I have a <code>grid</code> with column of checkbox in angular controller , and I want to set a <code>watch</code> on its checkbox cells click , </p>
  
  <p>for this I use <a href="https://github.com/mleibman/SlickGrid/wiki/Slick.Grid#getSelectedRows" rel="nofollow">getSelectedRows()</a> which would indicate whether the index array of the selected cell was changed . </p>
  
  <p>Here is the code - </p>
  
  <pre><code>$scope.grid = new Slick.Grid(...)
  $scope.$watch('$scope.grid.getSelectedRows()', function(newVal, oldVal){
       console.log(arguments);
  });
  </code></pre>
  
  <p>but when I toggle on any of this grid checkbox  - it doesn't enter to the watcher function .</p>
  
  <p>How to make it really watch to my checkbox click's ? </p>