btcd was changed to send the block hash for new block notifications as
a big endian string, so type assert as a string and convert to a
btcwire.ShaHash.
Each wallet needs its own handler running and listening to replies
from btcd, so that wallet can be synced to disk with the new tx or
utxo information. Another rounter to map from addresses to wallets
could have been written, but we'll use the JSON Id router message
router instead.
