Added KeepConnected connection string parameter to determine the number of seconds of connection inactivity before the client sends a ping request.
Added Load Balancing support - Several hosts with their ports can now be specified in the Host parameter of the connection string.
Added Target Session connection string parameter for managing Load Balancing functionality, possible values are SuppressLoadBalancing, Any, PreferStandby, PreferPrimary, Primary and Standby.
Added TargetSession property to the PgSqlCommand class to provide the possibility to overwrite the behavior of the same option set in the connection object.