* Update `github.com/ethereum/go-ethereum` package to 1.8.1 branch. Part of #638
* Fix code due to some signature changes. Part of #638
* use upstream for whisper backend
* Add patch to downgrade usage of Whisper v6 to v5 in some geth 1.8.1 vendor files. Part of #638
* Take into account the DNS rebinding protection introduced in 1.8.0 by adding exception for localhost. Part of #638
* Add patches required for cross-compiled builds starting with geth 1.8.0. Only applied during build. Part of #638
* Update expected JSON result in `TestRegressionGetTransactionReceipt()` and `TestCallRawResultGetTransactionReceipt()`. Part of #665
* Fix some failing e2e tests. Part of #638
* Address comments in PR #702. Part of #638
Pedro Pombeiro