Only in back-mdb; back-bdb needs work but it's deprecated;
not worth the effort. In particular txn, retry after deadlocks
makes the whole thing too messy.

Writer threads do their own wait using select/poll instead of
asking the listener thread. Eliminates one mutex+one condvar
per conn plus multiple wakeups of the listener thread. Also
fixes writetimeout to wait an exact time, instead of the
approximation used in the listener thread.

Note: I could not test the MozNSS patch due to the absence of
NSS PEM support on my machine. Given the review comments in
https://bugzilla.mozilla.org/show_bug.cgi?id=402712 I doubt that
trustworthy PEM support will be appearing for MozNSS any time soon.

Currently only implemented for OpenSSL.
Needs an option to set the criticality flag.

connection_<first/next>() takes a ber_socket_t *index, not int*.

Code comments belong in the code, not in commit messages.

Partial revert of 9e00b6cc:connection.c.

import ITS#6925 patch; fix peeraddr variable name clash in LDAP_CONNECTIONLESS code; fix scope of addr[] when inet_ntop(3) is used

Only affects delta-syncrepl - stop listening to clients while
refresh is running.

Caller provides and reuses a SlapReply it does not read after
initialization.  So reinitialize or move the declaration inwards.
In case of refint, move the rs parameter into refint_repair().

set and idletimeout is not.

has fully returned to the connection manager. This may result in
"deferring operation: binding" messages being logged again (ITS#3850) but
it should not cause any hangs.