Milter-greylist

Hi,

I've created a patch which optionally adds a 'Received-SPF' header when using 'libspf2' (probably could support 'libspf' and version varients if there's interest). Avoids having a seperate milter to achieve  this. One example where this is useful is prior to 'spamassassin'  as it will use the header rather than duplicating the lookups etc.
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Steven Hiscocks