Include core rules as bult-in text in bap

[GoogleCodeExporter]

Should have the core abnf rules come as part of the binary so instead of 
preloading abnf-core.txt 
there's a special --use-core-rules flag.

(This means convincing lex/yacc to scan from a file or a string, so is not a 
*no* no brainer)

Original issue reported on code.google.com by fen...@gmail.com on 15 Nov 2007 at 12:17

[pkyzivat]

This seems like a reasonable feature. OTOH, what I really want instead is a way for an abnf to explicitly import ABNF from an RFC/draft. But this should be an ABNF extension before it is a bap feature.

[AKayy2020]

37 #18