Improvements and fixes

A data logger that has gone silent no longer counts as healthy in a plant's tally.

• Graph tooltips now mark each curve with the events running at that moment, and a click pins the tooltip so those events can be opened.
• Where a plant already has a Mirox-hosted remote access server, another router or network can now be added to it instead of a second server.
• A plant's coordinates can now be entered as degrees, minutes and seconds or as decimal minutes, chosen under "Coordinate format".
• Each connected site in a plant's remote-access list now opens its own "Live status", and its tunnel address can be copied with one click.
• The edit dialog of a network device no longer shows the values of the device edited before it.
• A plant can now be given a build date in the future when it is created.