(struct x_output): Add scroll bar pixel colors, busy_cursor,

(struct x_output): Add scroll bar pixel colors, busy_cursor,
busy_window.  Remove cursor, computed_faces etc.  Add
white_relief_pixel, black_relief_pixel, white_allocated_p,
black_allocated_p, relief_background.
(struct x_display_info): Add gray pixmap, scroll_bar_pixel,
Xatom_Scrollbar, DONE, PAGE, image cache, resx, rey, smallest_char_width,
smallest_font_height.
(scroll_bar): Add x_widget_low and x_widget_high.
(FRAME_X_IMAGE_CACHE): New.
(FRAME_SMALLEST_CHAR_WIDTH): New.
(FRAME_SMALLEST_FONT_HEIGHT): New.
(struct relief): New.
(VERTICAL_SCROLL_BAR_PIXEL_HEIGHT): Removed.
(text_cursor_kinds): New.
(FRAME_FLAGS_BITMAP_HEIGHT): New.
(FRAME_FLAGS_BITMAP_WIDTH): New.
(FRAME_X_FLAGS_AREA_COLS): New.
(FRAME_MODE_LINE_BORDER_WIDTH): Removed.
(FRAME_MODE_LINE_HEIGHT): Removed.
(CHAR_TO_PIXEL_WIDTH): Rrwritten.
(PIXEL_TO_CHAR_WIDTH): Ditto.
(WINDOW_COL_PIXEL_X etc.) Removed.