Furnace Commands and Status. Modifications to existing DGNs and new DGNs to support control of circulation pumps.

Submitted by Gary Miller at Aqua-Hot. Required to support the increasing sophistication of hydronic heating systems, such as independent circulation pumps, integrated current sensors, and other sensors and features.

The following are modified:
1FFF6h WATERHEATER_COMMAND
1FFF7h WATERHEATER_STATUS

New DGNs
1FE99h WATERHEATER_STATUS_2
1FE98h WATERHEATER_COMMAND_2
1FE97h CIRCULATION_PUMP_STATUS
1FE96h CIRCULATION_PUMP_COMMAND