(x_get_glyph_string_clip_rect): Take internal border

(x_get_glyph_string_clip_rect): Take internal border
into account for full-width windows.  Don't add scroll bar width
to width of clip rect.
(x_draw_glyph_string_box): Add 1 to right x of full width lines.
(x_set_glyph_string_background_width): Add 1 to background width.
(x_draw_glyphs): Take internal border into account for full-width
lines.