(QCmnemonic, QCdefalut_char)
(QCdecode_translation_table, QCencode_translation_table)
(QCpost_read_conversion, QCpre_write_conversion): New variables.
(get_translation_table): Return a list of translation tables if
necessary.
(decode_coding): Call get_translation_table with ENCODEP 0.
(char_encodable_p): If translation_table is non-nil, always call
translate_char.
(Fdefine_coding_system_internal): Accept list of translation
tables as :encode-translation-table and :decode-translation-table.
(Fcoding_system_put): New function.
(syms_of_coding): Declare new symbols. Defsubr
Scoding_system_put.