adds description page url to thumb.

OK, this is some thought I was having regarding the thumbs we generate, since these are often used by external people, with no good way for attribution or anything.

This patch (untested since I don't run mediawiki), extends the imagemagick command that we run with an option that (should) add the URL of it's description page to the PNG file. I think it can be very useful.

Version: unspecified
Severity: enhancement

Attached: