Document how to get exit status of a popen() command.

behind the shell window on NT.

symbols is needed, define these in Python.h with a Py_ prefix.

exception -- return it as a tuple.  Seems useful in promiscuous mode.

- Changed name of fat interpreter to PythonFAT (Python conflicted with toplevel
  folder of the same name, unfortunately)

"don't close window on exit" feature to work.

- a dummy main program was added, so we can use the standard MW MSL
  runtime library for main programs (in stead of rolling our own, as we
  did previously).

- c2pstr has moved to a different include file