[ale] Monitor aspect ratio scaling

[Ken Arromdee]

The problem is that a typical LCD monitor has a 1280x1024 resolution, which
is not a 4:3 aspect ratio.  If you run in a mode which is a 4:3 aspect ratio,
(say, 800x600), it could either scale it up to fit the entire monitor (in
which case the picture is distorted), or it could scale it up to fit a 4:3
subsection of the monitor, leaving black bars at the top and bottom.

There seems to be no way to find out which of those two a monitor does.