Add wallet drain (send all) support for L-BTC.
Fix ELIP-151 computation, note that ELIP151 wallets will generate different addresses.
At startup if you had existing signers, wallets or assets, you might incur in some errors. To upgrade the state, if the error involves:
"asset_insert", get the contract, remove the line instate.lockand insert again asset from cli"load_wallet", replace with"wallet_load""signer_load_software", add,"persist":true