Improvements and fixes

The clear-sky curve is complete again. A device's web interface opens on its own start page again.

• The clear-sky curve no longer breaks off between yesterday midday and midnight.
• A device's web interface opens on its own start page again, not on a link that no longer works.
• A plant's operating state is right again straight after the on-site agent restarts, instead of staying unknown until it next changes.
• The data logger a combiner box or string is read from is now shown, as it already was for inverters.
• The manufacturer of a device found by a network scan is now filled in from its hardware address.
• Expected energy from the irradiation sensor and from satellite data is now also kept as a live running total, next to the live expected power.