* `ElectrumUpdate::missing_full_txs` now returns a `Vec<Txid>` so we don't keep a reference to the passed-in `graph`. * `ElectrumUpdate::finalize*` methods now takes in `missing` txids instead of `full_txs`. `Client::batch_transaction_get` is called within the methods. Other changes: * `wallet::ChangeSet` is now made public externally. This is required as a wallet db should implement `PersistBackend<wallet::ChangeSet>`.