Set the window menu flag for application-common menus

Set the window menu flag for application-common menus

* hildon/hildon-program.c:
(+hildon_program_window_set_common_menu_flag): Set or remove the
menu flag from a window only this doesn't have its own menu.
(+hildon_program_set_common_menu_flag): adjust menu flag for
all windows in the program.
(hildon_program_add_window),
(hildon_program_remove_window): add/remove the menu flag when
a window is added to the program.

Fixes: NB#137814 (Indicator for view menu in app title area)