* [DCG_ABNF,SC] Separate module for ABNF-inspired DCGs, comping from DCG_META.
* [DCG_ABNF,NEW] Finalized the implementation of non-sharing multi-calls of DCGs, i.e. 'm*n'// and variants.
* [DCG_ABNF,NEW] Added wrappers around 'm*n'//: '*m'//, 'n*'//.
* [DCG_CONTENT,FIX] The quote used in quoted//2 can now be uninstantiated.