usr.sbin: remove unnecessary CONSTCOND, lint no longer needs it

Since 2021-01-31, lint no longer requires a CONSTCOND comment in a
do-while-0 statement since this is a common code pattern, especially in
statement-like macros.

sed -i -E 's,} while \(/\* ?CONSTCOND ?\*/ ?0\),} while (0),' */*.[ch]

add parens around defines with expressions that could expand poorly
depending on the usage.

branches: 1.7.16;
according to C99 6.5.15 in a conditional expression, both
operands should be of compatible types.

So, use ((void)0) here to match `void dbprintf()'

Format string annotation.

- always set *to_buf to a timestamp, even if there was none reported/parseable
(Frank Kardel).
- merge the timestamp copying code to one place.
- factor out the debugging printf function.

PR/47861: Fredrik Pettai: keep track of the address family for each socket
opened and don't send the a message to the wrong family type.

branches: 1.3.6; 1.3.8; 1.3.12;
Add queue macros SLIST_FOREACH_SAFE, STAILQ_FOREACH_SAFE, STAILQ_LAST,
SIMPLEQ_CONCAT, and SIMPLEQ_LAST.

Remove seperate definitions outside of queue.h.

branches: 1.2.2;
Remove trailing whitespace.

Import syslogd SoC project by Martin Schuette:
- new syslog protocol api syslogp(3) that supports structured data
and draft-rfc timestamps
- reliable tcp connections with queueing
- encrypted connections