PATCH - improvements for imap_headerinfo()

Hi all, After getting done with a pretty large PHP4 project, I have a patch I would like to submit for php_imap.c in the IMAP extension. Here is what this patch does: imap_headerinfo() really only needs envelope info whereas the current version fetches all headers and requires a BODY.PEEK. This patch also reduces the overhead of having to convert the structure returned from the call to mail_fetchheader_full() into an ENVELOPE structure, when mail_fetch_envelope() actually returns an ENVELOPE struct (saves some mallocs and frees). This patch also deprecates the 'defaulthost' parameter (it is no longer needed). I don't get rid of it in the patch but we may want to create imap_headerinfo() as an alias (to maintain old backward compatibility) and get rid of that parameter in a new function. Thanks, Adam