Dear Maintainer,

I added an option to have the value written into the tag
come from the substitution of other tag values and/or the filename
according to a pattern.

Just as you can use a pattern for the filename to rename to, you
can use a pattern for the tag value.

I had downloaded some files with DownThemAll asking to name
the files from the link text. The filename was more accurate as
a tittle than the title tag, so I wanted to replace the tittle
with the filename and the old title.

Maybe I should have changed the tag class and introduce the old filename
as a variable for renaming the file too.

I'm not sure how lively this package is, so I'm just sending a patch
that worked for me in case anyon emight find it useful.

I'm sending this to debian because I'm not finding upstream, the url
http://www.travisshirk.net/eyeD3/releases/ gives 404 Not Found