Fix implementation to host our Mailing List, and mirror lore.kernel.org with grokmirror

[auyer]

related docs:
https://github.com/mricon/grokmirror/blob/master/grokmirror.conf

http://public-inbox.org/clients.html
http://public-inbox.org/public-inbox-clone.html
http://public-inbox.org/public-inbox-fetch.html