* locale/langinfo.h: Add entries for default_missing information.
* locale/C-ctype.c: Add initializers for new fields.
* iconv/gconv_trans.c: If nothing matched, try to use default_missing
information.
* locale/categories.h: Add entries for all LC_CTYPE values.
* locale/programs/ld-ctype.c (ctype_output): Write out default_missing
information.
* localedata/tst-trans.c: Write out an error message if class is
not found.