[feeds] Launchpad serves feeds with a 1hr TTL

[Stefano Rivera]

$ lynx -head -dump http://feeds.edge.launchpad.net/ibid/latest-bugs.atom
HTTP/1.1 200 OK
Date: Wed, 06 Jan 2010 22:05:16 GMT
Server: zope.server.http (HTTP)
X-Powered-By: Zope (www.zope.org), Python (www.python.org)
Content-Length: 35924
Expires: Wed, 06 Jan 2010 23:05:16 GMT
Vary: Cookie,Authorization
Last-Modified: Wed, 06 Jan 2010 22:03:44 GMT
Cache-Control: max-age=3600
X-Cache-Control: max-age=3600
Content-Type: application/atom+xml;charset=utf-8
Age: 138
X-Cache: HIT from nutmeg.canonical.com
X-Cache-Lookup: HIT from nutmeg.canonical.com:3128
Via: 1.0 nutmeg.canonical.com:3128 (squid/2.6.STABLE18)
Via: 1.0 feeds.edge.launchpad.net
Connection: close

If we tell the bot to poll every 300 seconds, it'd be nice if it actually did that rather than grabbing a cached response.