constructors. There is no backward compatibility. Not everything has
been tested.
* aiff.{py,doc}: deleted in favor of aifc.py (which contains its docs as
comments)
* imghdr.py: added jpeg recognition
* torgb.py: added jpeg conversion
* tzparse.py: use functions from time instead of calendar
* whatsound.py: add /ufs/guido/biin/sgi to $PATH when calling 'whatsound'