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.

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

Moved a bunch of logic up from Folder.

Moved many facilities up to ObjectManager.

Note that the previous check in also included a rename of
PrincipiaFnd to ZopeFind (with PrincipiaFind retained as an alias).

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

(effectively) inheriting permissions settings.
That is, a class' permission settings are the union of whatever
settings it has with settings in all base classes.

raised.  fixed to return null