QPID-5513: HA backup fails if number of replicated queues exceeds number of channels.

The problem:
- create cluster of 2 brokers.
- create more than 32768 queues (exceeds number of channels on a connection)
- backup exits with critical error but
- client creating queues receives no error, primary continues with unreplicated queue.

The solution: Primary raises an error to the client if it attempts to create
queues in excess of the channel limit. The queue is not created on primary
or backup, primary and backup continue as normal.

In addition: raised the channel limit from 32k to 64k. There was no reason for
the smaller limit. See discussion: http://qpid.2158936.n2.nabble.com/CHANNEL-MAX-and-CHANNEL-HIGH-BIT-question-tp7603121p7603138.html

New unit test to reproduce the issue, must create > 64k queues.

Other minor improvements:
- brokertest framework doesn't override --log options in the arguments.
- increased default heartbeat in test framework for tests that have busy brokers.

git-svn-id: https://svn.apache.org/repos/asf/qpid/trunk@1561206 13f79535-47bb-0310-9956-ffa450edef68