(Qvalid_codes): New variable.

(Qvalid_codes): New variable.
(coding_category_name): Include "coding-category-ccl".
(detect_coding_ccl): New function.
(setup_coding_system): Setup coding->spec.ccl.valid_codes from the
coding system priority `valid-codes' for CCL based coding systesm.
(detect_coding_mask): Check also a CCL based coding system.
(Fupdate_coding_systems_internal): Renamed from
Fupdate_iso_coding_systems.
(syms_of_coding): Change property char-table-extra-slot of
translation-table to 1.  Initialize and static pro Qvalid_codes.