feat(core): grid menus accessible

 - When the grid opens the focus is automatically set to the first element
in the list. When the menu closes the focus is automatically reutnred to
the menu button that opened that list except for when the column is
hidden. When the column is hidden the focus is set to the master grid
menu.
 - Also adds the ability to have screen reader only buttons in the menus.
The example of this is the 'close' menu item that only appears when the
focus is over it.
 - Updates e2e tests to reflect menu item addition.
 - The menu now has an additional item that is visible to screen readers
only and only becomes visible when focused. This adds one item to all of
the tests that are counting the number of elements that are 'displayed'.

misc/tutorial/102_sorting.ngdoc

@@ -238,8 +238,8 @@ columnDef option will cause sorting to be applied after the `cellFilters` are ap
       });
 
       it('click one menu, then click another menu, expect undisplay and redisplay on second click', function() {
-        grid1.expectVisibleColumnMenuItems( 0, 3 );
-        grid1.expectVisibleColumnMenuItems( 1, 3 );
+        grid1.expectVisibleColumnMenuItems( 0, 4 );
+        grid1.expectVisibleColumnMenuItems( 1, 4 );
       });
 
       it('toggle gender, expect Alexander Foley to move around', function() {

misc/tutorial/303_customizing_column_menu.ngdoc

@@ -128,8 +128,8 @@ See the example below for usage.
           })
       });
 
-      it('2 menu items in second column, implying no hide option and no remove sort option', function () {
-        gridTestUtils.expectVisibleColumnMenuItems( 'grid1', 1, 2 );
+      it('3 menu items in second column, implying no hide option and no remove sort option', function () {
+        gridTestUtils.expectVisibleColumnMenuItems( 'grid1', 1, 3 );
       });
 
       it('Long press opens menu in second column', function () {
@@ -181,14 +181,14 @@ See the example below for usage.
           });
       });
 
-      it('6 visible items in the third column, implying hide option', function () {
-        gridTestUtils.expectVisibleColumnMenuItems( 'grid1', 2, 6 );
+      it('7 visible items in the third column, implying hide option', function () {
+        gridTestUtils.expectVisibleColumnMenuItems( 'grid1', 2, 7 );
       });
 
-      it('click header to sort third column, 7 visible items in the third column, implying remove sort option', function () {
+      it('click header to sort third column, 8 visible items in the third column, implying remove sort option', function () {
         gridTestUtils.clickHeaderCell( 'grid1', 2 )
           .then(function () {
-            gridTestUtils.expectVisibleColumnMenuItems( 'grid1', 2, 7 );
+            gridTestUtils.expectVisibleColumnMenuItems( 'grid1', 2, 8 );
           });
       });
     });

misc/tutorial/401_AllFeatures.ngdoc

@@ -112,7 +112,7 @@ All features are enabled to get an idea of performance
         it('should not duplicate the menu options for pinning when resizing a column', function () {
           element( by.id('refreshButton') ).click();
           gridTestUtils.resizeHeaderCell( 'grid1', 1 );
-          gridTestUtils.expectVisibleColumnMenuItems( 'grid1', 1, 11);
+          gridTestUtils.expectVisibleColumnMenuItems( 'grid1', 1, 12);
         });
       });
   </file>