extended version of gnu bc.

• fixed some warnings and errors in bc.y when compiling with bison
• added bitwise |, &, ~ operators ( or, and, xor )
• added support for 0xhexval input, when 0xhexval constants are found, output is printed in both hex, and decimal.
• added '-e' option, to evaluate expression from commandline
• made to compile with readline versions >=4.3

• bc-1.06-wj.diff
  diff with original 1.06 bc version
• bc.exe
  cygwin compiled version.
• machine-doc.txt
  description of internal bc execution engine