This is needed to allow redeem/refund of P2SH without having an actively synced and initialized wallet. It also ultimately avoids us having to retain the wallet entropy in the trade bot states. Various safety checks have been introduced to make sure that a disposable wallet is never used for anything other than P2SH redeem/refund.
This has been modified to a) use full public keys instead of PKH, and b) hand off all transaction building, signing, and broadcasting to the (heavily customized) Pirate light wallet library.
Currently, new transactions take a very long time to be included in each block (or reach the intended recipient), because each node has to obtain a repository lock and import the transaction before it notifies its peers. This can take a long time due to the lock being held by the block minter or synchronizer, and this compounds with every peer that the transaction is routed through.
Validating signatures doesn't require a lock, and so can take place very soon after receipt of a new transaction. This change causes each node to broadcast a new transaction to its peers as soon as its signature is validated, rather than waiting until after the import.
When a notified peer then makes a request for the transaction data itself, this can now be loaded from the sig-valid import queue as an alternative to the repository (since they won't be in the repository until after the import, which likely won't have happened yet).
One small downside to this approach is that each unconfirmed transaction is now notified twice - once after the signature is deemed valid, and again in Controller.onNewTransaction(), but this should be an acceptable trade off given the speed improvements it should achieve. Another downside is that it could cause invalid transactions (with valid signatures) to propagate, but these would quickly be added to each peer's invalidUnconfirmedTransactions list after the import failure, and therefore be ignored.
Importing has to be single threaded since it requires the database lock, but there's nothing to stop us from validating signatures on multiple threads, as no lock is required. So it makes sense to separate these two functions to allow for possible multi threaded signature validation in the future, to speed up the process.
Everything remains single threaded in this commit. It should be functionally the same as before, to reduce risk.
