v4.9.2

Changelog

• f266593 Add address for POIs (#404)
• 02bb99f Prevent POI image from vertically overflowing too much (#395)
• e1c9bdb Show layer selector only if more that one layer (#411)
• a7b5226 add a / alpha component to json color mapping export
• c45f002 tweak trains and trainlines displayed zoom (#412)