rss2book release 13

[geekraver]

I did some more work on non-RSS 'feeds'. They now go through the same code path as most of RSS, so things like extracting links from the content work. I also made a few other changes:

- HTML URLs can use @yyyy, @yy, @mm and @dd as metacharacters that get expanded to date elements. If you specifu an URL with one or more of these, and you have the Number Of Days set to a non-zero value, rss2book will expand it to a separate URL for each day and concatenate the reults

- I added a Content Reformatter field; you can use this to add extra HTML content (e.g. <BR>s) where this is useful.

As always, necessity was the mother of invention and I had an end goal in mind, namely being able to pull down a weeks worth of Dilbert strips as a single PDF. You can do that now, although the Sunday comic seems to get clipped on the right edge.