Probe latencies now recorded before messages are added to the delivery manager.  This prevents the lock acquire time from overinflating xMax
-- Delivery Manager now supports two versions of the delivery protocol.  The version to be used can be selected by using the enum deliveryType.
-- V1 is the old delivery protocol.
-- V2 is a more efficient version of the delivery protocol that does not remove placeholders from the delivery set in normal conditions.  Instead it simply iterates over the ph and continues processing the delivery set.
-- DMProfiler class added to store profiling data for comparing delivery performance.