Revert revs 1.29 and 1.30, to make it easier to pullup an alternative fix.

Ok'ed by christos@
http://mail-index.netbsd.org/source-changes-d/2014/11/15/msg007338.html
Appease gcc48 -Werror=strict-aliasing warning by filling cksum via union.

Discussed in source-changes-d@ thread and tested on TT030.
Should be pulled up to netbsd-7 (if NetBSD/m68k 7.0 will switch to gcc48).
Consistently wrap long lines in ioconf.c.
Refactor.
Simpfily code by assuming suffix is a single character.