fix(#5041): Ensure length watchers transmit data

When in fastWatch mode, watcher methods returns the length of
their array being watched. When this value (integer). This value
(int) is then being passed to the watcher's callback overwriting
the array.

Author: Brice Leroy

src/js/core/directives/ui-grid.js

@@ -51,10 +51,10 @@
           }, dataWatchFunction) );
         } else {
           deregFunctions.push( $scope.$parent.$watch(function() { return $scope.uiGrid.data; }, dataWatchFunction) );
-          deregFunctions.push( $scope.$parent.$watch(function() { return $scope.uiGrid.data.length; }, dataWatchFunction) );
+          deregFunctions.push( $scope.$parent.$watch(function() { return $scope.uiGrid.data.length; }, function(){ dataWatchFunction($scope.uiGrid.data); }) );
         }
         deregFunctions.push( $scope.$parent.$watch(function() { return $scope.uiGrid.columnDefs; }, columnDefsWatchFunction) );
-        deregFunctions.push( $scope.$parent.$watch(function() { return $scope.uiGrid.columnDefs.length; }, columnDefsWatchFunction) );
+        deregFunctions.push( $scope.$parent.$watch(function() { return $scope.uiGrid.columnDefs.length; }, function(){ columnDefsWatchFunction($scope.uiGrid.columnDefs); }) );
       } else {
         if (angular.isString($scope.uiGrid.data)) {
           deregFunctions.push( $scope.$parent.$watchCollection($scope.uiGrid.data, dataWatchFunction) );