Make signrawtransaction work on offline wallets.
Make signrawtransaction work on offline wallets.

It should not assume that the chain RPC client is available.

While here, remove calls that import scripts and start rescans for
multisig outputs.  There is absolutely zero reason why this should be
performed by signrawtransaction, which should have no side effects.

jrick/btcwallet,jrick/dcrwallet,jrick/dcrwallet,jrick/btcwallet,decred/dcrwallet,decred/dcrwallet