(struct window): Add vscroll.

(struct window): Add vscroll.
(struct window): New member cursor_off_p.
(struct window): Remove phys_cursor_glyph.
(struct window): New members phys_cursor_ascent and
phys_cursor_descent.
(struct window): New flag pseudo_window_p.
(struct window): Add left_margin_width, right_margin_width.
New member last_cursor.
(WINDOW_LEFT_MARGIN): Remove FRAME_LEFT_SCROLL_BAR.
(WINDOW_TO_FRAME_VPOS): Convert window vpos
to frame vpos.
(WINDOW_TO_FRAME_HPOS): Convert window hpos to frame hpos.
(FRAME_TO_WINDOW_VPOS): Convert frame vpos to window vpos.
(FRAME_TO_WINDOW_HPOS): Convert frame hpos to window hpos.
(WINDOW_TOPMOST_P): Added.
(struct window): Rewrittenf for new glyphs.