* keyboard.c (read_key_sequence): Don't confuse mock input with

* keyboard.c (read_key_sequence): Don't confuse mock input with
	function-key-map expansion, and continue reading mock events when
	the current sequence is unbound.

	* keyboard.c (read_key_sequence): After providing a prefix symbol
	for a mouse event, modify the mouse event to indicate that that
	won't need to be done again, by putting the event's position
	symbol in a list.

	* keyboard.c (read_key_sequence): When returning mock input which
	has run off the end of the current maps, make sure the events get
	echoed, and make it into this-command-keys.

	* keyboard.c (read_key_sequence): When re-reading a previously
	read mouse click which requires a prefix symbol, make sure to set
	last_real_key_start appropriately, so we can properly drop
	button-down events.