Log Message:
Update to 5.820:

2008-11-05  Release 5.820

Main news is the ability to control the heuristics used to determine
the expiry time for response objects.

Gisle Aas (8):
      Reformat later parts of Changes
      Add a paragraph to summarize the motivation for releases since 5.815
      all_pod_files_ok();
      Fix POD markup error
      Calculation of current_age with missing Client-Date.
      The age/freshness methods now take an optional 'time' argument
      More correct matching of 'max-age' in freshness_lifetime method
      The freshness_lifetime method now support options to control its heuristics