fix filter-dnsbl build when asr is not in libc
enable build of backends and filters
remove log line prefix by getpid()
do not create two streams after all, it doesn't work on FreeBSD
Merge branch 'master' into portable

Conflicts:
	smtpd/Makefile
	smtpd/filters/filter-dnsbl/Makefile
realpath() require destination buffer to be at least PATH_MAX.
Merge branch 'master' into portable
remove bogus Makefile
fix typo in reject rule parsing
Merge branch 'master' into portable
small glitches
All scheduler backend functions now return an int instead of void
to report potential internal errors.
shutdown the table process on imsg error instead of sending
a PROC_TABLE_FAIL message.
various fixes in external queue backend and API.
initialize the scheduler before chrooting and droppring privileges
remove sc_ev from struct smtpd and use a local variable where needed.
call imsg_free() where appropriate.
Merge branch 'master' into portable