(ucs-mule-to-mule-unicode): Don't define

(ucs-mule-to-mule-unicode): Don't define
this translation-table name here.
(utf-translation-table-for-encode): New translation-table name.
(utf-fragmentation-table): Renamed from utf-8-fragmentation-table.
(utf-defragmentation-table): New variable.
(ucs-mule-cjk-to-unicode): Renamed from utf-8-subst-rev-table.
(utf-subst-table-for-encode): New translation-table name.
(ucs-unicode-to-mule-cjk): Renamed from utf-8-subst-table.
(utf-subst-table-for-decode): New translation-table name.
(utf-fragment-on-decoding): Renamed from
utf-8-fragment-on-decoding.  Correctly handle the case that
unify-8859-on-encoding-mode is off.  Handle mule-utf-16-le and
mule-utf-16-be too.
(utf-translate-cjk): Renamed from utf-8-translate-cjk.  Handle
mule-utf-16-le and mule-utf-16-be too.
(ccl-decode-mule-utf-8): Refer to utf-translation-table-for-decode
and utf-subst-table-for-decode.
(ccl-encode-mule-utf-8): Refer to utf-translation-table-for-encode
and utf-subst-table-for-encode.
(mule-utf-8): Fix `safe-charsets' property, put `dependency'
property.