* xdisp.c (redisplay_window): Invalidate width_run_cache, if the

* xdisp.c (redisplay_window): Invalidate width_run_cache, if the
buffer's display table doesn't match the width table the cache was
built for.
(display_text_line): Use compute_motion to skip forward to the
left edge of the window when the window is hscrolled; this is
faster than rendering all the characters into the bit bucket when
the hscroll is large.
Doc fixes.
(display_count_lines): Call scan_buffer with new args.