to call from DTML. This wants to be a getattr, but
getattr is hard so we're not going to do it yet.

delattr and the _zclass_ class.

Added return from initialize product so products can be
modified after initialization.

a bug that affected COPY in specific overwrite situations, added
a borg-specific header to dissuade ie5 from sending multiple
requests to see if we have FrontPage extensions.

problem and to make a first step toward getting rid of evil
__getstate__.

to get around acquisition problem and to make a first step toward
getting rid of evil __getstate__.

convert to extension classes to make permission machinery
work properly.  This needs some more thought.