(display_mode_line): Use faces for inverse video mode line whenever possible.

(display_mode_line): Use faces for inverse video mode line whenever possible.

(echo_area_display): Shift display_string past a left-side scroll bar.
(redisplay_window): Likewise.
(redisplay_internal): Shift cursor past a left-side scroll bar.
(redisplay_window): Likewise.
(try_window_id): Likewise.
(display_text_line): Likewise.
(redisplay_internal): Shift charstarts past a left-side scroll bar.
(display_text_line): Likewise.
(redisplay_internal): Use new macro WINDOW_FULL_WIDTH_P.
(redisplay_window): Likewise.
(display_text_line): Likewise.
(display_text_line): Shift output past left-side scroll bar.
(display_text_line): Use new WINDOW_RIGHTMOST_P macro.
(display_text_line): Don't pad right columns unless using
a right-side scroll bar.  Don't draw vertical bars unless there
isn't any kind of scroll bar.
(display_string): Likewise.
(display_mode_line): Use new macros WINDOW_LEFT_MARGIN,
WINDOW_RIGHT_MARGIN, and WINDOW_FULL_WIDTH_P.
(display_string): Use new macro WINDOW_RIGHTMOST_P.