Python milter

Enhanced documentation, Python 2.6 support, and bugfixes. Support was added for automatic feature negotiation with the MTA using Python decorators.

The rcpt for SRS rejections is logged. Parsing of
MAIL FROM into email and fullname was improved.
No-DSN CBV was implemented. A check is done cfor
porn words in MAIL FROM fullname. IPs are now
banned for too many bad MAIL FROMs or RCPT TOs.
Temperror policy is supported in sendmail access.
Gossip TTL was configured. AddrCache, parse_addr,
and iniplist were added to the Milter package.
parse_header was added to Milter.utils. A sample
spfmilter.py milter was added. The pymilter and
pymilter-spf packages were split out. Milter apps
were moved to /usr/lib/pymilter.

The spf module was moved to pyspf. Code to prevent
PTR cache poisoning was added. More lame bounce
heuristics were added. A fallback to plain CBV
when template is missing was added.

This release fixes "out of thread resources"
errors caused by spammers
who use tarpits.

A simple trusted_forwarder implementation was
added. The access_file neutral policy was fixed.
The Received-SPF header was moved to the beginning
of the headers. Keyword info was supplied for all
results in the Received-SPF header. The guessed
SPF result was moved to a separate header. The
build was fixed to activate smfi_insheader only
when SMFIR_INSHEADER is defined. A NULL MX in
spf.py is now handled. In-process GOSSiP server
support was added (to be extended later). The CBV
cache is expired and auto-whitelist entries are
renewed.