SpamFilters

A bug in the rulesets that process SpamAssassin's
"X-Spam-Status" mail header was fixed. Some
sendmail comments are now m4 comments. Regular
expression (RE) character classes were replaced
with character ranges to reduce string lengths.
More spoof characters were sprinkled on
reorganized subject filters. The optional virus
filters were updated. The contrib directory was
updated. The test directory was removed.

This release adds build-time options to decode RFC-2047 "Subject" text,
reject mail with missing or empty "Subject" text, and log a summary of
rejecting rulesets. The subject filters have been expanded, and the
processing of them is much more efficient. Support scripts and programs
have been updated and/or added.

SpamFilters now depends on sendmail's m4 build
hierarchy; the details of this dependency are in
the INSTALL section of the documentation. Two
build-time options were added: a "spam policy"
mail header and a slew of anti-virus Subject
filters. A little optimization was done, and the
subject filter RE is now fuller.