Re: [PATCH] Add request_header_add option and [request|reply]_header_* manglers fixes

This is the new version of the request_header_add patch. It is a little
bigger than the original it make many changes, but I hope it is OK and
did not add bugs to squid.

This patch:
  - The format/* interface used to format added headers.
  - The logformat codes used for request_header_add option
  - Add the new %ssl::>cert_subject and %ssl::>cert_issuer log formating
codes
  - The request_header_add project has as requirements login,client ip
address and the server name. The %ul, %>a and %{Host}>h can be used with
this patch.
  - AccessLogEntry is a RefCountable class in this patch.

I hope it is OK.