refactor: doSpecialZone- split up into separate functions for each zone type
doSpecialZone: use annotations to control which special zone processing is done
tiles.rc: move pollution values from Java code to tiles.rc

This patch maintains exact values for every tile, even where it
is probably wrong.
pollution: airport's radar dish should emit pollution just like rest of airport
pollution: industrial zone animations should emit pollution
pollution: coal plant animated tiles should emit pollution
applyZone: rewrite to use tiles.rc annotations
refactor: introduce new CityDimension class to encapsulate width/height
refactor: make getZoneSizeFor return CityDimension (width AND height)
strictness: getZoneSizeFor must be called on a zone-center tile
cleanup: remove a bunch of unused tile constants