Expires: headers for Packages.gz, Sources.gz

[Matt Zimmerman <mdz@debian.org>]

Would it be possible to have (at least the primary) mirrors send Expires:
headers for Packages.gz and Sources.gz?  They should expire at the time of the
next mirror pulse; usually this can be estimated to be (mtime + 24 hours).

With Apache, this is as easy as adding:

ExpiresActive on
ExpriesDefault M86400

to the appropriate config block(s).  This would allow caches to be very
accurate about the freshness of their copies of these files.

-- 
 - mdz