(last_nonmenu_event): New var.

(last_nonmenu_event): New var.
(syms_of_keyboard): New Lisp var.
(read_key_sequence): Use that instead of prev_event.

(read_char): Call read_char_menu_prompt here.
Accept 4 new args to pass to it.  Include them in recursive call.
Don't delay before starting echo if prev_event was a mouse event.
Test for eof in batch mode now understands C is a Lisp_Object.
(read_key_sequence): Don't call it here; always call read_char.
Don't change last_event_buffer after a mouse menu input.
(read_char_menu_prompt): Arg PROMPT deleted.
Return nil if nothing to do.

(read_key_sequence): Keep track of prev_event.
Pass new proper args to read_char_menu_prompt.
(read_char_menu_prompt): New arg prev_event.  Use Fx_popup_menu.
Handle any number of keymaps, not just LOCAL and GLOBAL.
Invert meaning of arg PROMPT.  Test of menu_prompting was backwards.

(keymap_table): No longer static.