- Finally fixed the bug in compile() and exec where a string ending

- Finally fixed the bug in compile() and exec where a string ending
  with an indented code block but no newline would raise SyntaxError.
  This would have been a four-line change in parsetok.c...  Except
  codeop.py depends on this behavior, so a compilation flag had to be
  invented that causes the tokenizer to revert to the old behavior;
  this required extra changes to 2 .h files, 2 .c files, and 2 .py
  files.  (Fixes SF bug #501622.)