Extend parser to accept binary constants that begin with '0b' or '0B'. * NEWS: Announce change: * lex.ll: Define NUMBIN to be 0[bB] followed by 0,1, or '_'. Define NUMBER to be NUMREAL|NUMHEX|NUMBIN. *lex.ll (looks_like_bin): New function to detect 0[bB] prefix. *lex.ll (handle_numbe): Call looks_like_bin() and if found then convert binary string to double. * parser.tst: Add tests for new behavior.