* window.c (window_internal_width): New function, which accounts

* window.c (window_internal_width): New function, which accounts
	for scrollbars if present.
	* lisp.h (window_internal_height, window_internal_width): Add
	extern declarations for these.
	* dispnew.c (direct_output_for_insert, direct_output_forward_char,
	buffer_posn_from_coords): Use window_internal_width instead of
	writing out its definition.
	* indent.c (compute_motion): Doc fix; mention scrollbars and
	window_internal_width.
	(pos_tab_offset, Fvertical_motion): Use window_internal_width
	instead of writing it out.
	* window.c (Fpos_visible_in_window_p, Fwindow_width, Fscroll_left,
	Fscroll_right): Same.
	* xdisp.c (redisplay, try_window, try_window_id,
	display_text_line): Same.

	* termhooks.h (mouse_position_hook): Doc fix.
	(set_vertical_scrollbar_hook): This doesn't return anything any
	more, and doesn't take a struct scrollbar * argument any more.
	(condemn_scrollbars_hook, redeem_scrollbar_hook,
	judge_scrollbars_hook): Doc fixes.
	* term.c (mouse_position_hook): Doc fix.
	(set_vertical_scrollbar_hook): This doesn't return
	anything any more.  Doc fixes.
	* keyboard.c (kbd_buffer_get_event): Receive the scrollbar's
	window from *mouse_position_hook and pass it to
	make_lispy_movement, instead of working with a pointer to a struct
	scrollbar.
	(make_lispy_event): We don't need a window_from_scrollbar function
	anymore; we are given the window directly in *EVENT.
	Unify the code which generates
	text-area mouse clicks and scrollbar clicks; use the same code to
	distinguish clicks from drags on the scrollbar as in the text area.
	Distinguish clicks from drags by storing a copy of the lispy
	position list returned as part of the event.
	(button_down_location): Make this a lisp vector, rather than an
	array of random structures.
	(struct mouse_position): Remove this; it's been replaced by a lisp
	list.
	(make_lispy_movement): Accept the scrollbar's window as a
	parameter, rather than the scrollbar itself.
	If FRAME is zero, assume that the other arguments are garbage.
	(syms_of_keyboard): No need to staticpro each window of
	button_down_location now; just initialize and staticpro it.
	* window.c (window_from_scrollbar): Function deleted; no longer
	needed.
	* xdisp.c (redisplay_window): Just pass the window to
	set_vertical_scrollbar hook; don't pass the scrollbar object too.
	* xterm.c (XTmouse_position): Don't return a pointer to the
	scrollbar for scrollbar motion; instead, return the scrollbar's
	window.