Pyspf

* Strict processing limits per newly official SPF RFC
* Fixed several parsing bugs under RFC
* Support official IANA SPF record (type99)
* Extended SPF processing results beyond strict RFC limits
* Validate spf.py against test suite, and add Received-SPF support to spf.py
* Support best_guess for SPF
* Support SPF delegation

* Arik Baratz pointed out endian problems using socket.inet_ntoa() and
socket.inet_aton(). Use struct.pack("!L", struct.unpack("!L") to fix.

* Replace DNS.addr2bin() and DNS.bin2addr() with socket.inet_ntoa() and
socket.inet_aton(). New code supports n, n.n, and n.n.n formats for IPv4
addresses, and gets rid of annoying Python 2.4 future warnings

* Greg Connor discovered that SPF queries to altavista.com were broken.
This was testing to see if a mechanism needs to be macro expanded _before_
leading ? + - characters were removed.
* Fixed include handling to be a real mechanism: -include must work.

* Forgot to include new test file in distribution.
* Forgot CHANGELOG in distribution.

* Add %{o} (original sender domain) macro
* The ./spf.py {spf} {ipaddr} {sender} {helo} command line didn't print
out the results. Oops.
* Support default= so Meng's test 6 'v=spf1 default=deny' works
* Any IP address '127.*.*.*' automatically pass, so all Meng's tests work
* Follow DNS CNAMES
* Cache DNS results, including additional info, reducing DNS query load
* Support Python 2.2 (doesn't have bool, True, False: those are
added in Python 2.2.1)