code: function _setProjectRoot(rootEntry) {
          var d = new $.Deferred();
          model.setProjectRoot(rootEntry).then(function () {
              d.resolve();
              model.reopenNodes(PreferencesManager.getViewState("project.treeState", _getProjectViewStateContext()));
          });
          return d.promise();
      }
docs: @private
  
  Sets the project root to the given directory, resetting the ProjectModel and file tree in the process.
  
  @param {Directory} rootEntry directory object for the project root
  @return {$.Promise} resolved when the project is done setting up