[devtools] bases for instrumenting / debugging standard propagation hooks * a class that helps writing command to check propagation, detecting standard errors and picture the propagation as a graph * a class to instrument sets used to configure standard propagation hooks closes #3171980

Latest changes 
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* table of `all latest changes`_

Links below is providing useful RQL query example.

.. _all latest changes: view?rql=Any+M%2CX+WHERE+X+modification_date+M+ORDERBY+M+DESC+LIMIT+30