SF Patch 686254 "Run IDLEfork from any directory without set-up"

Allows IDLE to run when not installed and cwd is not the IDLE directory.

I took the liberty of moving it to the startup scripts since once IDLEfork
is again a part of Python it will be superfluous and I don't want it to
be forgotten.  But it is very useful for those using IDLEfork standalone!

M CREDITS.txt
M NEWS.txt
M idle
M idle.py
M idle.pyw