Add in Nifty versions for the Block of Coal. I don't know why I didn't do this at the start, but might be a good idea. I don't know how this would be a good idea, but then again, I made Nifty, so anything goes.

These will have a burn value similar to the Block of Coal, but the following will have to happen:

• Stairs are the equivalent of 3/4 of a Block of Coal
• Slabs are the equivalent of 1/2 of a Block of Coal
• Fences will vary, but I might make them about 1/3 of a Block of Coal

Additional Nifty blocks, if added later, will vary their value based on how I see fit.