[EFL][WK2] Support sub menu in ewk context menus
https://bugs.webkit.org/show_bug.cgi?id=114729

Patch by Michał Pakuła vel Rutka <m.pakula@samsung.com> on 2013-05-17
Reviewed by Christophe Dumez.

Added submenu support in EwkContextMenu and an API function to receive
Ewk_Context_Menu from submenu context menu item. A test case was added
for new API function.
EwkContextMenu is now an EwkObject allowing multiple instances of submenu
to be used in different submenu type context menu items.

* UIProcess/API/efl/ewk_context_menu_item.cpp:
(EwkContextMenuItem::EwkContextMenuItem):
(ewk_context_menu_item_new):
(ewk_context_menu_item_parent_menu_get):
(ewk_context_menu_item_submenu_get):
* UIProcess/API/efl/ewk_context_menu_item.h:
* UIProcess/API/efl/ewk_context_menu_item_private.h:
(EwkContextMenuItem::create):
(EwkContextMenuItem::parentMenu):
(EwkContextMenuItem::subMenu):
(EwkContextMenuItem):
* UIProcess/API/efl/ewk_context_menu_private.h:
(EwkContextMenu::ewkView):
(EwkContextMenu):
* UIProcess/API/efl/tests/test_ewk2_context_menu.cpp:
(showContextMenu):

git-svn-id: http://svn.webkit.org/repository/webkit/trunk@150254 268f45cc-cd09-0410-ab3c-d52691b4dbfc