* 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'
* 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()