Update old-style definitions to ANSI, remove a couple of register
definitions along the way. Fixed gcc 4.1 build (thank you vax)

WARNS=4

changes related to lib/20576 and lib/20577.
- add wcstok() and wcswcs(),
- add wcstok(3),
- move btowc() and wctob() into each ctype modules,
- bump ctype interface ABI version,
- bump i18n

changes related to lib/20576 and lib/20577.
- add wcstok() and wcswcs(),
- add wcstok(3),
- move btowc() and wctob() into each ctype modules,
- bump ctype interface ABI version,
- bump i18n modules' minor and
- update sets.
and fix a stupid bug in _RUNE_ISCACHED macro.

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sprinkle in _DIAGASSERT() as appropriate

move wcs* and wmem* from lib/libc/locale to lib/libc/string.