Reconnect with different username

[Rob Eden]

Reconnecting to the same host with a different username doesn't user the new username since the information is found in the outbound_session_map.

Scenario:

1. Connection with user "foo" to a host.
2. Don't close the original connection, connection with user "bar"

Now, it's not clear what the behavior should be. Options:

1. Throw an exception on the second connection attempt saying we're already connected with different credentials.
2. Disconnect the original connection and attempt to reconnect with the new credentials.

[Rob Eden]

This was fixed quite a while ago with session reconnection tokens... stale bug