ssl-strict-check, ill wait till another branch gets committed to
move this forward as it will be much simpler
Implement a feedback mechanism which allows the mta to "hold" envelopes
in the scheduler when it has too many tasks for a given relay, and
"release" them later.  It limits the number of "inflight" envelopes.
Add a global limit on the number of inflight envelopes. When the limit
is reached, the scheduler stops scheduling mta/mda envelopes until the
number of inflight envelopes drops.

While there, limit the mta envelope recall to 100 envelopes by default.
bump dict key size to fix possible crash, this is a temporary solution
reworked ssl
Merge branch 'master' into 293-strict-ssl

Conflicts:
	smtpd/parse.y
	smtpd/smtpd.h
backport manpage fix from OpenBSD
document that mails enqueued via the local socket are tagged "local".
move forward with tls strict verify, works for relay rules, not
relay via rules yet
- implement listen on foo tls-require verify
- fix relay via with cert verification
fix a segv
Merge branch '293-strict-ssl'
remove spurious log
display warnings if local certificate is used before validity or after expiration
even if we're returning a safe string, use a format in snprintf calls
rename "ssl" to "secure" and avoid a token clash with openssl internals while at it
rename "ssl" to "secure"
rename ssl to secure
a couple bzero() added just to be safe
negative rules + doc