[C++ Broker, clients] AMQP 0-10 windows clients can not connect to --no-auth broker

Broker

./qpidd --auth no

Windows client

spout -b my-broker:5672 amq.topic

Fails with "Not authenticated!"

The behavior change was in the broker as part of QPID-6325. Arguably the change is a good thing as it prevents clients connecting to the broker with no name. However, it makes for a poor out-of-the-box experience with a no-auth broker rejecting connections with an auth error.

Clients can make a connection by adding:

--connection-options "{username:dummy}"
or
--connection-options "{sasl-mechanisms:ANONYMOUS}"

But the change breaks years of accumulated self tests that work just fine against older versions of qpidd.

The proposal to fix this is to make the Windows client provide the same connection defaults as linux cyrus sasl.