New in version 0.9.2:
Version 0.16 fix.

New in version 0.9.1:
1 Coal to 50 woods -> 1 Coal to 50 raw woods.

1 Coal to 50 coals.
1 Coal to 50 raw woods.
1 Coal to 50 iron-ore.
1 Coal to 50 copper-ore.
1 Coal to 50 uranium-ore.
1 Coal to 50 stones.
1 Coal to 2000 crude-oil.
1 Coal to 5000 water",