1. Implement processing of user code in subprocess MainThread.  Pass loop
   is now interruptable on Windows.
2. Tweak signal.signal() wait parameters as called by various methods
   to improve I/O response, especially on Windows.
3. Debugger is disabled at this check-in pending further development.

M NEWS.txt
M PyShell.py
M rpc.py
M run.py
4 files changed