Release 4.1.1 - Stability, db robustness, and some other random things

[whilei]

Goal of the milestone: stabilize client behavior for edge cases, improve database robustness
Release deadline: Nov 1

Central:

• Issue spontaneous re-sync #274 - further investigate database corruption/restart; reproducible? Lead: @tzdybal
• PR core: recover blockchain data in case of corrupted header data #277 - finish and merge PR resolving above
• Issue Geth classic 4.0.0 goes out of sync #346 - resolve; reproduce or invalid?
• Issue Incorrect estimateGas #339 - resolve; reproduce or invalid?

Miscellaneous:

• Issue Installable via homebrew #361 - setup homebrew installation
• Issue unimplemented: several debug api methods #364 - resolve; remove unimplemented methods from ethereum_js
• PR implement debug logging/verbosity api methods #365 - review and merge; implement logging-related methods for debugApi
• Issue ECIP-1017 monetary policy: possible misinterpretation #352 - resolve rounding ambiguity related to Parity/Geth implementation difference. See related links from issue page, especially ECIP-1017 ETC monetary policy and emission schedule ECIPs#15. This is more an ECIP human-consensus issue than a code issue. Lead: @whilei

[whilei]

Closing in favor of using milestone system, moved to https://github.com/ethereumproject/go-ethereum/milestone/9.