bitmap_con.c

Also, fix up window behaviour... allow dragging it larger and smaller,
disable maximize, and don't allow snapping bigger or smaller than
the user area.

Finally, when r2y tables aren't installed, set the aspect ratio to
xsize x ysize so all the aspect "stuff" works properly.

With this, GDI is now the default output mode for Windows.  Auto
order is now:

X11 -> GDI -> SDL -> Win32 Console or Curses -> ANSI

Maybe for 2.0 I'll do a Wayland and Core Graphics driver too. :D