URL naming
----------

/$LISTNAME/?before=$GIT_COMMIT                  -> HTML only
/$LISTNAME/all.html?before=$GIT_COMMIT          -> HTML only, includes replies
/$LISTNAME/index.atom.xml                       -> Atom feed
/$LISTNAME/all.atom.xml                         -> Atom feed, includes replies
/$LISTNAME/mid/$MESSAGE_ID.html                 -> HTML content
/$LISTNAME/mid/$MESSAGE_ID.txt                  -> raw text

We use file name suffixes on all of these (except /) so URLs may easily
cached/memoized using a static file server.