* message.el (message-mode-map): Keybinding for `gnus-delay-article'.

* message.el (message-mode-map): Keybinding for `gnus-delay-article'.
(message-mode-menu): Menu item for same.

* gnus-group.el (gnus-group-make-menu-bar): Menu item for sending
delayed articles.

* gnus-delay.el (gnus-delay-send-drafts): Do nothing if
nndraft:delayed does not exist.
(gnus-delay-initialize): Don't set up keymap, that's done from
message.el now.
(gnus-delay, gnus-delay-group, gnus-delay-header)
(gnus-delay-default-delay, gnus-delay-default-hour): Customize.