A simple transaction test on a 3 node cluster generates a lot of errors and
rollback messages in the broker logs even though the test code never rolls back a
transaction. E.g.

  qpid-cluster-benchmark -b 20.0.20.200 -n1 -m 1000 -q3 -s2 -r2 --send-arg=--tx --send-arg=10 --receive-arg=--tx --receive-arg=10

The errors are caused by queues being deleted while backup brokers are using
them. This happens a lot in the transaction test because a transactional session
must create a new transaction when the previous one closes. When the session
closes the open transaction is rolled back automatically. Thus there is almost
always an empty transaction that is created then immediately rolled back at the
end of the session. Backup brokers may still be in the process of subscribing to
the transaction's replication queue at this point, causing (harmlesss) errors.

This commit takes the following steps to clean up the unwanted error and rollback messages:

HA TX messages cleaned up:
- Remove log messages about rolling back/destroying empty transactions.
- Remove misleading "backup disconnected" message for cancelled transactions.
- Remove spurious warning about ignored unreplicated dequeues.
- Include TxReplicator destroy in QueueReplicator mutex, idempotence check before destroy.

Allow HA to suppress/modify broker exception logging:
- Move broker exception logging into ErrorListener
- Every SessionHandler has DefaultErrorListener that does the same logging as before.
- Added SessionHandlerObserver to allow plugins to change the error listener.
- HA plugin set ErrorListeners to log harmless exceptions as HA debug messages.

Unrelated cleanup:
- Broker now logs "incoming execution exceptions" as debug messages rather than ignoring.
- Exception prefixes: don't add the prefix if already present.

The exception test above should now pass without errors or rollback messages in the logs.

git-svn-id: https://svn.apache.org/repos/asf/qpid/trunk/qpid@1564010 13f79535-47bb-0310-9956-ffa450edef68

The test was failing due to incorrect handling of the transaction lifecycle:
- Failing to handle the automatic rollback of the empty TX at session close.
- Deleting the tx-q before all backups were finished with it.

The fixes include
- Make tx-q auto-delete, deleted only when the TxReplicators cancel their subscriptions.
- Use markInUse/releaseFromUse on the primary to keep the tx-q until the primary is done.
- Count TxReplicators for auto-delete (unlike normal QueueReplicators)
- Improved error handling and log messages
- Handle *incoming* exceptions on a federation link by passing to ErrorListener
- QueueReplicator catches incoming not-found and resource-deleted exceptions
  - close the backup bridge, handle race between subscribe and delete.
- Simplify QueueSnapshots, remove need for snapshot map.

git-svn-id: https://svn.apache.org/repos/asf/qpid/trunk/qpid@1541146 13f79535-47bb-0310-9956-ffa450edef68

git-svn-id: https://svn.apache.org/repos/asf/qpid/trunk/qpid@1514192 13f79535-47bb-0310-9956-ffa450edef68

git-svn-id: https://svn.apache.org/repos/asf/qpid/trunk/qpid@1496466 13f79535-47bb-0310-9956-ffa450edef68

- Clean up code for accounting for sent frames
- merged Connection and ConnectionState into Connection

git-svn-id: https://svn.apache.org/repos/asf/qpid/trunk/qpid@1494639 13f79535-47bb-0310-9956-ffa450edef68

- was only used by removed cluster support

git-svn-id: https://svn.apache.org/repos/asf/qpid/trunk/qpid@1491584 13f79535-47bb-0310-9956-ffa450edef68

git-svn-id: https://svn.apache.org/repos/asf/qpid/trunk/qpid@1425038 13f79535-47bb-0310-9956-ffa450edef68

git-svn-id: https://svn.apache.org/repos/asf/qpid/trunk/qpid@1424133 13f79535-47bb-0310-9956-ffa450edef68

git-svn-id: https://svn.apache.org/repos/asf/qpid/trunk/qpid@1424125 13f79535-47bb-0310-9956-ffa450edef68

git-svn-id: https://svn.apache.org/repos/asf/qpid/trunk/qpid@1424121 13f79535-47bb-0310-9956-ffa450edef68