flier can be placed on occupied feature
rules update: dragon and followers are permitted on features outside the
City of Carcassonne (accesible by portal or flier)
rules update: City of Carcassonne (Count expansion) treat as city for
farm scoring and King purposes.
FARM_CITY_SCORED_ONCE custom rule removed - 2nd edition scoring is
obsolete and may leads to confusion together with some expansions