Description of problem:
exchange's property 'auto-delete' is ignored or invalid.

QMF shows the 'autoDelete' property as False all the time, 
and delete action when last receiver unsubscribe is invalid, since the receiver makes the subscription queue and the unsubscribe is applied on that queue and not relayed to the exchange.

Thus the auto-delete property is invalid for exchange
-or-
property should possible to set and last subscription has to be relayed to exchange to make it work.

Version-Release number of selected component (if applicable):
qpid-cpp-*-0.22-29
qpid-cpp-*-0.18-18

How reproducible:
100%

Steps to Reproduce:
1. create a auto-delete exchange with sender
./spout "ex;{create:always, node:{type:topic,'x-declare':{'auto-delete':True}}}"
2. check QMF
./qmf2_list_objects --query-data exchange/ex | ipython
3. subscribe to the exchange, and let unsubscribe
./drain "ex"

Actual results:
{'_create_ts': 1386781433415679174,
 '_delete_ts': 0,
 '_object_id': {'_agent_epoch': 699,
                '_object_name': 'org.apache.qpid.broker:exchange:ex'},
 '_schema_id': {'_class_name': 'exchange',
                '_hash': 'c9bb43df-44ac-63d5-cc1c-6a032025c97d',
                '_package_name': 'org.apache.qpid.broker',
                '_type': '_data'},
 '_update_ts': 1386781455003296482,
 'arguments': {},
 'autoDelete': False,
 'bindingCount': 0,
 'bindingCountHigh': 0,
 'bindingCountLow': 0,
 'byteDrops': 91,
 'byteReceives': 91,
 'byteRoutes': 0,
 'durable': False,
 'msgDrops': 1,
 'msgReceives': 1,
 'msgRoutes': 0,
 'name': 'ex',
 'producerCount': 0,
 'producerCountHigh': 0,
 'producerCountLow': 0,
 'type': 'topic',
 'vhostRef': {'_object_name': 'org.apache.qpid.broker:vhost:org.apache.qpid.broker:broker:amqp-broker,/'}}

exchange has property 'autoDelete': False and it's not deleted after last receiver

Expected results:
auto-delete should work with exchanges same as with queue
- OR - 
the property should be removed from QMF

Additional info:
Please move the bug on qpid-qmf based on final resolution