Lazy connection association when trying to lazily associate a ManagedConnection
to a connection handle, it seems not to associate a connection in
ConnectionManager. This is a regression from v2.
Also, the ManagedConnection of JDBC-RA need to disassociate both itself and
physical connection from the connection holder so that cleanup is complete.
[This is not harmful, but still it is a better approach]
When associateConnection is called on ManagedConnection, the ManagedConnection
is associated with the user's connection but the ManagedConnection does not seem
to reset the reference of its user's connection to the one that is passed.
Hence raising this issue to take care of all the three.