This fallback to std::map & std::set for older compilers
Use UNORDERED_SET as an example in decoration and ore biome sets
Use UNORDERED_MAP as an example in nameidmapping
- Node placement code moved to Lua
- Mineral system removed (added default:stone_with_coal and default:stone_with_iron).
- MapBlock and MapNode serialization updated.
- Mapgen: Frequency of iron increased.
- node_dig callback and related changes.