of the recent WARNS commits. The idea is:
1) FreeBSD id tags should follow vendor tags.
2) Vendor tags should not be compiled (though copyrights probably should).
3) There should be no blank line between including cdefs and __FBSDIF.
o main returns int not void
o use return 0 at end of main when needed
o use braces to avoid potentially ambiguous else
o don't default to type int
o #ifdef 0 -> #if 0
Reviewed by: obrien and chuckr
