[ZPatterns] ZPatterns not TTW, step 2

[R. David Murray]

Well, after a little discssion with Christian Scholz on IRC, and
some wandering around in the code, I figured out that I don't need
property sheets (I think).  From my point of view there isn't much
point in having a zclass, but it *looks* from the code like not
using a zclass will lead to problems (I haven't tried to bypass
manage_setStorage, so I don't know for sure that it is, but it
looks like it).

Anyway, it looks at first glance like this will work for me (declare
this zclass, use it in manage_setStorage, but have the python code
in methods on the base class just read and write attributes directly),
so I'm satisfied.

The reason I thought I needed property sheets was that in my previous
TTW effort manage_changeProperties was the only way I found to get
attribute setting to be recognized (I was doing the setting from
pythonscripts).

--RDM