merge 3.20.9 into 3.21
Fix conflict in unittest_postgres.py by changing sources configuration
in PostgresTimeoutConfiguration.__init__ so it happens *after*
setUpModule().
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