weather 5.x-2.0

Changes:

• Don't display "No data" for empty fields, remove them altogether. Closes: #113549
• Dynamically determine width and height of displayed images to allow alternative images. Closes: #123616
• Display of units is now completely configurable, also adding "knots" as windspeed unit. Closes: #102330
• The parser now supports windspeed units other than only knots in METAR reports. Closes: #128852
• If JavaScript is enabled, use the AJAX version of the country and place lookup. Otherwise, the ICAO textfield will be shown without the country and place selection boxes. Closes: #115339, #115842
• The country and place selection boxes do no longer provide the entry "- None -", as it wasn't accepted anyway.
• Add Pristina to the list of supported ICAO codes
• Optionally, the block can display the raw METAR data. Closes: #111377
• Add new translation to Russian. Thanks to Alexander Lavrinenko. Closes: #127460
• Add new translation to Hungarian. Thanks to Zsolt Rohberg. Closes: #128852