Revision 1767

- Romcc preprocessor bug fixes, (The code size went down about 350 lines.. :)
- Preprocessor constant expression evaluation is no long a special case so
  unsigned long values can not be used.
- Undefined macros are not converted to 0.  But a big warning is printed.
- Garbage at the of an #include directive is now done in tokens instead of
  in characters.
  This allows comments after an #include directive.
- Repaired a previously unnoticed regression in constant expression
  evaluation.  Logical expressions can now be evaluated again.