Log Message:
update to spamassassin 3.1.5.  relevant changes:

	bug 5018: update RegistrarBoundaries with new list of 2TLDs
	bug 5020: drop __OUTLOOK_DOLLARS_MSGID, replace with the superset
	rule __OE_MSGID_2
	update replace_license_blocks, have it deal with C-style comments
	better, put a sample commandline in place
	bug 4492: bayes_ignore_header was case sensitive
	add logging, enable zmi and doc mass-checks
	bug 5049: allow commented lines in gpgkeyfile and channelfile files
	bug 4952: set a default value for DEF_RULES_DIR_, LOCAL_RULES_DIR,
	and LOCAL_STATE_DIR.  this fixes an issue where third-party code
	which hasn't been updated to deal with LOCAL_STATE_DIR can still
	use updates.
	bug 4848: Pyzor, DCC, and SpamCop plugins weren't looking at the
	right place to see the 'dont_report_to_...' options
	bug 4843: skip text/calendar parts when generating the body text
	arrays
	bug 5013: deal octal obfuscation of IP addrs in URLs
	bug 5049: handle comments and whitespace in sa-update config files
	and fix an error in channel name validation
	bug 4981: remove broken urirhssub support for regexp subrule and
	make perldoc match the code
	bug 5060: backport ArchiveIterator changes for rule-QA system,
	namely: the AICache caching subsystem for faster mass-checks, support
	for combined --head/--tail semantics, more verbose 'showdots' to
	avoid buildbot timeouts, and a new intra-child IPC me chanism for
	multi-child mass-checks
	bug 5034: fix endless loop possible from bad input or network error
	bug 5065: implement whitelist_from_dk
	bug 4823: clarify M::SA::Plugin documentation