[session/transaction] pass the session object to the Transaction __init__ This simplify access to variables. As we are moving more and more logic and states in the Transaction it will greatly helps in future commit.

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