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)
* sndhdr.py: renamed to whatsound.py; use new aifc module for AIFF/AIFC
* ftplib.py: added close() (closes without sending QUIT command)
* aifc.py: documented close()