1. CLEANUP: Arrow/line drawing code in separate module [[dcg_arror]].
2. CLEANUP: Added documentation to [[dcg_ascii]].
3. EXTENDED: Added weights to hexadecimal digits in [[dcg_ascii]].
4. EXTENDED: Consistently added type argument to bracket predicates
             in [[dcg_ascii]].
5. CLEANUP: No longer use within module ascii_-prefix for predicates
            in [[dcg_ascii]].
6. ADDED: Rewrote [[dcg_cardinal]] using [[radix]].
7. ADDED: Rewrote DCG codes (module [[dcg_code]]) using [[radix]].
8. CLEANUP: Separate module for quoting: [[dcg_quote]].
9. EXTENDED: Added support for several UNICODE characters.
10. CLEANUP: Updated a few formal grammars in line with [[dcg_ascii]].