* NaturalWonders initial commit
* Created models/ruleset/tile/NaturalWonder and assets/json/NaturalWonders
* MapGenerator now spawns NaturalWonders in random compatible random locations
* MapParameters has a noNaturalWonders option
* TileInfo has naturalWonder property (set to null if none)
* TileInfo and UnitMovementAlgorithms correctly manages stats and consider the tile unpassable and unimprovable
* Notification and happiness on NaturalWonder discovery
* El Dorado discovery bonus, Spain unique
* Doubled tile yields for Spain
* NaturalWonders implemented as TerrainType + Fountain of Youth promotion
* Images issue #124
* NaturalWonder TileImages (Fantasy) and Overlay (Default)
* NaturalWonderOverlay.png : https://www.flaticon.com/free-icon/mount-fuji_2166259
* Bugfix
* Added translations
* Italian translations
* Fix translation issue
* missing space after = in template.properties breaks translations
* Improved NaturalWonder spawn logic
* Great Barrier Reef spawns on 2 contiguous tiles
* Each wonder has specific spawn requirements
* Number of wonders spawned scales with map radius
* Fix unused import
