Terrain: Array of extra specific clean times
Internal change only, not yet to be exposed to ruleset: store per-extra clean time on terrains. Initially it's either existing pollution clean or fallout clean time, or smaller one (faster action), if both are set for the terrain.
Internal change only, not yet to be exposed to ruleset: store per-extra clean time on terrains. Initially it's either existing pollution clean or fallout clean time, or smaller one (faster action), if both are set for the terrain.