register-capability-menu-item in drscheme:unit:frame<%>

Registers the menu item that was most recently added as being controlled by the capability key. This means that the (boolean) value of the capability determines if the menu item is present in the menu (the capability is checked when the menus are cliked on).

This assumes that the menu items in this menu are not moved around, except by the this capability. If they are, things can go funny (i.e., no good checks are in place).

Note that the capability must be registered separately, via drscheme:language:register-capability.

• (send a-drscheme:unit:frame register-capability-menu-item key menu) -> void
     key : symbol
     menu : (is-a? menu%)