When troubleshooting node issues we must often change the log4j2 XML configuration by hand and then restart the SolarNode service, which by default is not monitored for automatic reloading. Although the XML configuration does allow turning on automatic reloading, one must still change the configuration by hand which can be error-prone for users unfamiliar with the syntax.

This ticket proposes some simple dynamic logging configuration support. By "simple" I mean just adjusting any logger level at runtime, without having to edit the configuration file. It would be OK if the dynamic configuration was ephemeral, and lost if the SolarNode service is restarted (reverting to the XML file's configuration).

Two methods of changing the log levels should be supported:

1. a SolarNet instruction, so logging could be adjusted via the SolarNetwork API
2. the SolarNode UI, so an administrator could directly manage the node's logging