For instance, Accounting Trnsaction Lines can be contained in a Accounring Rule Cell
of a Invoice Transaction Rule, and none of these provide a causality workflow, but
Accounting Transaction Line is also a possible child of a Accounting Transaction
in the Accounting Transaction Module.

git-svn-id: https://svn.erp5.org/repos/public/erp5/trunk@16830 20353a03-c40f-0410-a6d1-a30d3c3de9de