vcl: Make the Menu class really abstract.

Change-Id: I676b2673cbe32bfe7c6013588c19a557fdfc743d
vcl: It's a close button, there is no such a thing as a 'closer'.

Clean up at least vcl + what depends on that, but unfortunately there are
still some "Closer"'s left elsewhere...

Change-Id: I019c863d07ee62d701ff01c8d871334012c105f1