This patch adds a config option that adds mailto: links to the author's name in HTML views of articles.

Actually getting the author's name is a bit of a pain. I added two migrations. First, we add two fields to users: name and email. Next, we give article a user_id (and belongs_to :user) and then populate the user_id by matching articles.author == users.name.

This patch has only been lightly tested ("it works for me"-grade testing). The patch is generated against my current working tree, which includes the geourl and flickr patches (#153 and #154), plus a few other things. I'll perform more testing later today and produce an updated patch if required.