* [DCG_ABNF,NEW] Added very many new meta-DCGs.
* [DCG_ASCII,NEW] Added wrappers angular_bracket//[0,1].
* [DCG_CONTENT,NEW] Rewrote arrow//2 to be both generator and parser.
* [DCG_META,NEW] Added dcg_call_s//[1-6] allowing variables to be shared between DCG calls.
* [RECORD_JAR,NEW] Attempt to rewrite a difficult DCG module using the new DCG_ABNF (not yet tested).
* [RFC4234_BASIC,NEW] Added wrappers 'BIT'//2, 'DIGIT'//1, 'HEX'//2.
* [RFC4234_BASIC,SC] Removed '1*BIT'//1, easy to build using '+'// and 'BIT'//.