Refactored interfaces related to business process management and simulation. Nexedi refactoring should include "6th element" idea if possible, once it is better understood. 

git-svn-id: https://svn.erp5.org/repos/public/erp5/sandbox/amount_generator@35543 20353a03-c40f-0410-a6d1-a30d3c3de9de