bug#6491: 24.0.50; list-buffers should not throw away marks

[jidanni]

!v runs the command Buffer-menu-select, which is an interactive
!compiled Lisp function in `buff-menu.el'.
!
!It is bound to v, <menu-bar> <Buffer-menu-mode> <sel>.
!
!(Buffer-menu-select)
!
!Select this line's buffer; also display buffers marked with `>'.
!You can mark buffers with the m command.
!This command deletes and replaces all the previously existing windows
!in the selected frame.

The problem is 1) when me make marks with m, the cursor moves down, so
we have to move the cursor back up unless we want our v command to pull
in an unrelated buffer.

Well OK, just make the last keystroke a v instead of a m, as 2) our marks
get thrown away anyway at the next invocation of list-buffers... which
is in fact why I'm writing this bug, even though I know there are many
replacements for list-buffers. OK, never mind.

In GNU Emacs 24.0.50.1 (i486-pc-linux-gnu, GTK+ Version 2.20.1)
 of 2010-06-20 on elegiac, modified by Debian
 (emacs-snapshot package, version 1:20100619-2)