Include <string.h> and <locale.h>.

Include <string.h> and <locale.h>.
(langname_list): New variable.
(load_lang_script_list): Exclude invalid list elements.
(mlang__init): Initialize langname_list.
(mlang__fini): Unref langname_list.
(mlanguage__info): Adjusted for the change of English
name (symbol->M-text).
(mlanguage_name): Label it as obsolete.
(mlanguage_name_list): New function.