mod_smtpd overhaul

[Rian Hunter <ri...@MIT.EDU>]

Hi,

I just have committed mod_smtpd with changes that free it from
request_rec. There are now two major structures in mod_smtpd:
smtpd_conn_rec, and smtpd_trans_rec. These are distinguished by how
often these get cleared.

Also mod_smtpd no longer uses the ap_getline and ap_rprintf functions
for I/O. There are three new functions for I/O called smtpd_getline,
smtpd_respond_oneline and smtpd_respond_multiline. This should allow the
use of filters in mod_smtpd although I may have implemented this wrong.
Comments are requested.

Joe:
For the data command I still call ap_get_brigade with AP_MODE_GETLINE,
just because SMTP is a line oriented protocol was there any explicit
reason you wanted it to be called with AP_MODE_READBYTES?

You can check it out from
https://svn.apache.org/repos/asf/httpd/mod_smtpd/trunk/.
-rian