Blocks with reveal transactions that were loaded from disk could not be
distributed to other nodes before. This prevented new nodes with an old
blockchain state from synchronizing the blockchain.
This bug has now been fixed.
Miners should choose a transaction from the network based on its reward,
not as part of the mining variability.
That's why it's a bad idea to place the transaction as last block element.
Reorder the fields to make less room for harmful mining optimization.
