This fixes [28422] and testBPMEvaluation (PicklingError exceptions).
This reverts useless [30411].
It also allows to revert [31213].

git-svn-id: https://svn.erp5.org/repos/public/erp5/trunk@31791 20353a03-c40f-0410-a6d1-a30d3c3de9de