* keyboard.c (Fexecute_mouse_event): dyked-out function deleted.
We're not going to use this mouse interface.
(Vmouse_window, Vmouse_event, Vmouse_event_function,
Vmouse_left_hook, Vmap_frame_hook, Vunmap_frame_hook,
Vmouse_motion_handler): Variables deleted; they were to be used by
Fexecute_mouse_event.
(syms_of_keyboard): Same.
(command_loop_1): Remove dyked-out code to support
Fexecute_mouse_event.
(read_char): Same.
* keyboard.c (Vlast_event_frame): Don't define this window if
MULTI_FRAME is not #defined.
(syms_of_keyboard): Same.
(kbd_buffer_store_event): Don't try to work with Vlast_event_frame
if MULTI_FRAME is not #defined.
(kbd_buffer_get_event): Same.
* keyboard.c (Fdiscard_input): Removed dyked-out code from when
unread_command_char's quiescent value was -1, not nil.