[z3-five] packaging and five

[whit]

rocky and I were kicking around the idea of breaking out parts of five 
into separate python packages to allow for more granular upgrades in 
between manage zope releases(and possible provide some relief for 
compatibility straddling and version churning).

This could also allow for some setuptools based dependency management in 
the future.

Basic idea is that parts of five critical to using zope 3 in zope2 move 
into zope2 proper; optional parts move into python distributions.

thoughts?

-w