Improvements and fixes

Alarms an inverter raises about itself now reach the plant's event list. Restarts and moves of the on-site agent are recorded in the plant's activity list.

• The plant's event list now carries the alarms a Huawei or SMA inverter raises about itself, and closes them when the device withdraws them.
• The plant's activity list now records when its on-site agent was restarted or moved.