Update of the box function in themes to allow a difference in...

Update of the box function in themes to allow a difference in style/output/look of a box() depending on the position on the page.
Basically this is a 'nice version' of a hack that you could do as a theme author.
I've updated all the standard themes, but 3rd party themes will of course have to be updated by their authors, in the following manner:

- Replace the box() declaration:
< function box($subject, $content) {
> function box($subject, $content, $region = "main") {

- Replace the theme_account call:
< theme_account($this);
> theme_account("region", $this);

Note that you'll have to replace "region" with the correct region that the box is placed in. However if you have a one-column theme, you should use "all", and not for example "left" (if all boxes are on the left).
Usually the "region" here should be the same as the nearest theme_blocks() call.

Those theme authors who want to can make boxes that appear in the center look different from those that appear in the sides for example.