debug and packet trace logging.
Make this conditional on HAVE_SIGINFO. Presumably lack of SIGINFO as a
standard posix feature is why they went with different signals here in
the first place, but since we have it, let's use it.
- Enhance the built-in drop-privs support and use it instead of
having the rc.conf do it. Avoids log error on startup.
From OpenSolaris, with enhancements.
- Add dumping of the unicast server list to the DumpStateLog
debugging output, a'la Mac OS X.
- Fix a locking botch that caused warnings in the log.
- Fix FILE leak. From OpenSolaris.
- Build with MDNS_VERSIONSTR_NODTS a'la OpenSolaris, to exclude
__DATE__/__TIME__, for repeatable builds.
- log under "mdnsd" instead of "mDNSResponder" to reduce confusion.
