Further adjust frame/window scrollbar width calculations.

Further adjust frame/window scrollbar width calculations.

* window.c (apply_window_adjustment): Set
windows_or_buffers_changed.
(Fwindow_scroll_bars): Return actual scrollbar width.
* xfns.c (x_set_scroll_bar_default_width): Rename wid to unit.
For non-toolkit builds again use 14 as minimum width and set
FRAME_CONFIG_SCROLL_BAR_WIDTH accordingly.
* xterm.c (XTset_vertical_scroll_bar): Take width from
WINDOW_SCROLL_BAR_AREA_WIDTH.
(x_new_font): Rename wid to unit.  Base calculation of new
scrollbar width on toolkit used and make it analogous to that of
x_set_scroll_bar_default_width.
* w32fns.c (x_set_scroll_bar_default_width): Rename wid to unit.
(Fx_create_frame): Call x_set_scroll_bar_default_width instead
of GetSystemMetrics.
* w32term.c (w32_set_vertical_scroll_bar): Take width from
WINDOW_SCROLL_BAR_AREA_WIDTH.
(x_new_font): Make it correspond to changes in xterm.c.