Improvements and fixes

Network devices now have a cross-plant overview, and exports cover whole portfolios, coarser resolutions, correct tab files and clearer week labels.

• One overview lists the network devices of all your plants with their availability, and a plant's Dataflow page header counts its online and offline devices.
• In the export's metrics view you can now pick whole portfolios, and every plant you can reach inside them is included.
• Weekly, monthly, quarterly and yearly resolutions are offered wherever the chosen period allows them, and you can export a month as a single row.
• Turn on "Full weeks" and the first and last week of your selection are filled out to all seven days.
• The preview marks weeks that fall only partly inside your range with * and explains the mark; weekly points read CW12, daily points the day.
• Choosing the tab character as separator now really gives you a tab-separated file, and the preview shows values containing quotes or the separator correctly.
• Hovering a chart in the export now shows the metric's name instead of a code.
• The year list in the export no longer offers years after the current one.