(struct glyph_row): New members left_fringe_bitmap,

(struct glyph_row): New members left_fringe_bitmap,
right_fringe_bitmap, redraw_fringe_bitmaps_p for new fringe handling.
New members exact_window_width_line_p and cursor_in_fringe_p for
overflowing newlines into right fringe.
New members indicate_bob_p, indicate_top_line_p, indicate_eob_p,
and indicate_bottom_line_p for buffer boundaries and scrolling.
(enum fringe_bitmap_type): Add UP_ARROW_BITMAP, DOWN_ARROW_BITMAP,
FIRST_LINE_BITMAP, LAST_LINE_BITMAP, FILLED_BOX_CURSOR_BITMAP,
HOLLOW_BOX_CURSOR_BITMAP, BAR_CURSOR_BITMAP, HBAR_CURSOR_BITMAP,
and HOLLOW_SQUARE_BITMAP.
(draw_fringe_bitmap, draw_window_fringes, update_window_fringes):
Add prototypes.