ifconfig(8): Sync with FreeBSD a bit and various cleanups
* Sync ifconfig.c a bit with FreeBSD; replace several warnx() with
errx(), and improve error messages a bit.
* Remove unnecessary exit() after Perror().
* Sync if_clone.c with FreeBSD.
* Add inclusion guard to ifconfig.h.
* Make iseq() a static function for ifieee80211.c and regdomain.c,
replacing the duplicate definitions of it; and use iseq()
consistently to replace strncasecmp() and strcasecmp().
* Move "struct ident" from regdomain.c to regdomain.h, and add and use
"enum IdentType".
* Various whitespace cleanups.
* Cleanup header file inclusion: remove duplicates, and reorder a bit.
* Fix various signed vs. unsigned comparisons.
* Fix some compilation warnings, and raise WARNS to 3.
15 files changed: