Fix api documentation for scrollbars.

Accessing uiGridConstants scrollbars is possible via uiGridConstants.scrollbars.(ALWAYS|NEVER|WHEN_NEEDED), not uiGridConstants.scrollbar.(...)

Author: mamrehn

src/js/core/factories/GridOptions.js

@@ -196,17 +196,17 @@ angular.module('ui.grid')
        * @ngdoc boolean
        * @name enableVerticalScrollbar
        * @propertyOf ui.grid.class:GridOptions
-       * @description uiGridConstants.scrollbar.ALWAYS by default. This settings controls the vertical scrollbar for the grid.
-       * Supported values: uiGridConstants.scrollbar.ALWAYS, uiGridConstants.scrollbar.NEVER, uiGridConstants.scrollbar.WHEN_NEEDED.
+       * @description uiGridConstants.scrollbars.ALWAYS by default. This settings controls the vertical scrollbar for the grid.
+       * Supported values: uiGridConstants.scrollbars.ALWAYS, uiGridConstants.scrollbars.NEVER, uiGridConstants.scrollbars.WHEN_NEEDED.
        */
       baseOptions.enableVerticalScrollbar = typeof(baseOptions.enableVerticalScrollbar) !== "undefined" ? baseOptions.enableVerticalScrollbar : uiGridConstants.scrollbars.ALWAYS;
 
       /**
        * @ngdoc boolean
        * @name enableHorizontalScrollbar
        * @propertyOf ui.grid.class:GridOptions
-       * @description uiGridConstants.scrollbar.ALWAYS by default. This settings controls the horizontal scrollbar for the grid.
-       * Supported values: uiGridConstants.scrollbar.ALWAYS, uiGridConstants.scrollbar.NEVER, uiGridConstants.scrollbar.WHEN_NEEDED.
+       * @description uiGridConstants.scrollbars.ALWAYS by default. This settings controls the horizontal scrollbar for the grid.
+       * Supported values: uiGridConstants.scrollbars.ALWAYS, uiGridConstants.scrollbars.NEVER, uiGridConstants.scrollbars.WHEN_NEEDED.
        */
       baseOptions.enableHorizontalScrollbar = typeof(baseOptions.enableHorizontalScrollbar) !== "undefined" ? baseOptions.enableHorizontalScrollbar : uiGridConstants.scrollbars.ALWAYS;