[mythtv] Preview images in mythweb

[Torbjörn Jansson]

Why does mythweb use a fixed width and height for the preview images in the
recorded programs page?
This makes the preview images of recordins that use widescreen look
stretched out verticaly.

It looks much better if i comment out:
define('pixmap_width',  160);
define('pixmap_height', 120);

In conf.php, but it also says "Height and width of generated pixmaps (for
now, these are fixed - please do not change these numbers)"
Why should i not change them?

(160x120 seems to be the default size of 4:3 recordings)