do not build install regress by default
Reorganize the queue backends code so that builtins and external
backends only differ where necessary.
Merge branch 'portable' of ssh.poolp.org:/git/opensmtpd into portable
Merge branch 'master' into portable

Conflicts:
	smtpd/queue_fsqueue.c
Merge branch 'portable' of https://github.com/poolpOrg/OpenSMTPD into portable
Merge branch 'portable' of https://github.com/poolpOrg/OpenSMTPD into portable
open(2) needs an extra arg
Merge branch 'master' into portable
queue_fsqueue.c -> queue_fs.c
Merge branch 'master' into portable
queue_fsqueue.c -> queue_fs.c
Make sure *_envelope_walk() has the correct prototype everywhere.
It must fille the providied buffer with the envelope content if
found. Fix queue_proc.c and queue_api.c accordingly.
Merge branch 'master' into portable
fix typo
Merge branch 'master' into portable