[amqp1.0] Add identifying information to the connection properties advertised to the client

AMQP 1.0 provides a properties map in the Open performative that is sent when a connection is established. Currently, the standard has not defined the contents of this map, however, it would be useful to provide information that can be used to identify the broker.

We should prefix any symbols we introduce with 'x-qpid-...' (or maybe org.apache.qpid.?) to prevent clashes should the working group eventually define standard entries.

I would like to see the following entries added - this is just a suggestion and I'm open to other ideas:

x-qpid-product: 'qpidd',
x-qpid-version: '<the version of qpidd, else SNAPSHOT>'
x-qpid-proton-version: 'x.y' - the version of proton qpidd was built against

other stuff?