WIP: Python3
This is a merge request to track ERP5 support for Python3 (zope4py3 branch). See also the following merge requests:
Python3 business template support.IdTool: handle bytes for group_id on python3.- !2131 (merged)
- !2136 (merged)
Using slapos!1257 (merged) slapos!1670 (merged) for slapos.