Log Message:
Update sendmail to 8.15.2.

pkgsrc change:  default to enable TLS
- this has been requested a couple of times and most systems are going
  to have a recent enough version of openssl so in most cases there
  won't be additional dependencies

8.15.2/8.15.2	2015/07/03
	If FEATURE(`nopercenthack') is used then some bogus input triggered
		a recursion which was caught and logged as
		SYSERR: rewrite: excessive recursion (max 50) ...
		Fix based on patch from Ondrej Holas.
	DHParameters now by default uses an included 2048 bit prime.
		The value 'none' previously caused a log entry claiming
		there was an error "cannot read or set DH parameters".
		Also note that this option applies to the server side only.
	The U= mailer field didn't accept group names containing hyphens,
		underbars, or periods.  Based on patch from David Gwynne
		of the University of Queensland.
	CONFIG: Allow connections from IPv6:0:0:0:0:0:0:0:1 to relay again.
		Patch from Lars-Johan Liman of Netnod Internet Exchange.
	CONFIG: New option UseCompressedIPv6Addresses to select between
		compressed and uncompressed IPv6 addresses.  The default
		value depends on the compile-time option IPV6_FULL:
		For 1 the default is False, for 0 it is True, thus
		preserving the current behaviour.  Based on patch from
		John Beck of Oracle.
	CONFIG: Account for IPv6 localhost addresses in
		FEATURE(`block_bad_helo').  Suggested by Andrey Chernov
		from FreeBSD and Robert Scheck from the Fedora Project.
	CONFIG: Account for IPv6 localhost addresses in check_mail ruleset.
	LIBMILTER: Deal with more invalid protocol data to avoid potential
		crashes.  Problem noted by Dimitri Kirchner.
	LIBMILTER: Allow a milter to specify an empty macro list ("", not
		NULL) in smfi_setsymlist() so no macro is sent for the
		selected stage.
	MAKEMAP: A change to check TrustedUser in fewer cases which was
		made in 2013 caused a potential regression when makemap
		was run as root (which should not be done anyway).
	Note: sendmail often contains options "For Future Releases"
		(prefix _FFR_) which might be enabled in a subsequent
		version or might simply be removed as they turned out not
		to be really useful.  These features are usually not
		documented but if they are, then the required (FFR)
		options are listed in
		- doc/op/op.* for rulesets and macros,
		- cf/README for mc/cf options.