Log Message:
Update to duplicity-0.5.20:
New in v0.5.20 (2009/08/28)
---------------------------
Bugs fixed this release:
408059  Failure due to _logger.log failure for content with special
        characters: TypeError decoding Unicode not supported
412667  "duplicity remove-older-than" asks for passphrase even though
        not required
418170  [PATCH] file names longer then 512 symbols are not supported

New in v0.5.19 (2009/08/06)
---------------------------
Fixed problem where Cygwin was returning -1 for the
hard max open file limit.
On process that complete before waitpid(), log them
and return zero as the process return status.
Make sure 'invalid packet (ctb=14)' from gpg is not
a fatal error.
Copy changes from trunk for duplicity translation.
Allow handling of unicode filenames in log messages.
Ignore unicode() translation errors in log messsages.