World polish: forests, mountains, waterfronts and roads

User feedback on the dressed world: forests too dense, embankments and roads bare (fences, kerbs, stone banks, steps down to the water), mountains impassable but flat. Done when forests show open ground, mountains have real height, town rivers have quays and paved edges kerbs.

Done: groves and clearings, mountains rising from their foot (terraces tried and dropped for the smooth rise), quays with parapets and steps, kerbs, shored banks and jetties near roads, roadside fences. Ordering new kerb or quay-stair sprites was not needed.