tahoe-lafs.org upgraded

[Brian Warner]

Hi folks.. I just finished upgrading the machine that hosts
https://tahoe-lafs.org to the latest Ubuntu LTS. I think everything is
working correctly, but please let me know if you see anything broken.

cheers,
 -Brian

(I tried to move our Trac instance into a virtualenv, but for some
reason every time did that, the headers and footers of each page
disappeared. Pulled my hair out for an hour trying to track it down,
failed, and eventually reverted back to the global install. If anybody
has run into this error before, please let me know what the heck is
going on.. I couldn't figure it out)