Make FMP work with WorldEdit

Instead of replacing all tiles on chunk load, this substitutes a delegate map into the chunk that swaps all incoming tile entities if needed. This allows it to work with WorldEdit and pretty much anything else, as the swap is part of the integrated system of loading tiles. The delegate map helps by allowing other map swaps to happen with other mods, increasing compatibility, and if MC ever makes a more efficient chunk map the efficiency will carry over to this map as well.
Nowhere, just verifying contract for the Map. If `put` swaps then `putAll` should as well. It will eliminate surprises in the future.