[Zope-dev] ZPT: defer expression fix

PageTemplates have an undocumented features called defer:. It's a kind of lazy initialization of variables. I've fixed to issues in my tiran-zpt-pydefer branch (svn): * DeferWrappers weren't working inside a python expression because PythonExpr didn't know about them * DeferWrapper didn't cache the result of the expression like ordinary vars do. I would like to merge my branch into 2.7 and 2.8 if I get an ok. Christian