function stuff. Since each menu calls km_dokey() to get the 'op'
number to execute, the 'menu' argument to km_dokey() _is_ the
CurrentMenu. Hence, there is no need to explicitly save/restore the
CurrentMenu all over the code. The only places it is being captured
now is just before mutt_enter_comamnd() is called. This is to help
the 'exec' command completion code so that it knows which menu to
try and complete the function name from.
(From: Vikas Agnihotri <VikasA@att.com>)