* map [+africa] fixed misplaced misc_sound entity
* map [+frozen] added Corrupter UFO
* map [+frozen] added Gunboat UFO
* map [+frozen] added crashed Fighter UFO
* map [+frozen] added crashed Harvester UFO
* fixed tile descriptor and LICENSES entry for st_craft_crash_fighter.map
* map [+frozen] added missing snow particles to crashed Harvester map
* fixed frozen.ump
* map [+frozen] added crashed Gunboat UFO