Only start the notifier timeout once we've had a chance to check for updates. Otherwise the timeout could fire while we are waiting for the database to return any updates it might have

Fold _do_request_for_transaction into the methods that called it since it was a trivial wrapper around client.get_json

Use float rather than integer divisions to turn msec into sec - so timeouts under 1000msec will actually work

Don't make @unittest.DEBUG print the huge amount of verbosity generated by the synapse.storage loggers

Check the existance and versions of necessary modules when starting synapse, log which modules are used