* keyboard.c (this_command_keys): Make this a vector, instead of

* keyboard.c (this_command_keys): Make this a vector, instead of
	an array of Lisp_Objects.
	(this_command_keys_size): Deleted.
	(echo, add_command_key, Fthis_command_keys): Adjusted
	appropriately.
	(init_keyboard): Don't allocate it here.
	(syms_of_keyboard): Allocate it here, and staticpro it.

	* keyboard.c (read_char): Call ourselves with the appropriate
	number of arguments.
	(read_char_menu_prompt): If USED_MOUSE_MENU is zero, don't try to
	store things in it.

	* keyboard.c (modify_event_symbol): Arrange to set the
	click_modifier bit on otherwise unmodified mouse clicks.

	* keyboard.c (kbd_buffer_get_event): Remember that
	*mouse_position_hook may set *FRAME to 0; don't generate
	switch-frame events in this case.  Fix fencepost bug in fetching
	events from keyboard buffer.