* p2p/simulation: WIP minimal snapshot test
* p2p/simulation: Add snapshot create, load and verify to snapshot test
* build: add test tag for tests
* p2p/simulations, build: Revert travis change, build test sym always
* p2p/simulations: Add comments, timeout check on additional events
* p2p/simulation: Add benchmark template for minimal peer protocol init
* p2p/simulations: Remove unused code
* p2p/simulation: Correct timer reset
* p2p/simulations: Put snapshot check events in buffer and call blocking
* p2p/simulations: TestSnapshot fail if Load function returns early
* p2p/simulations: TestSnapshot wait for all connections before returning
* p2p/simulation: Revert to before wait for snap load (5e75594)
* p2p/simulations: add "conns after load" subtest to TestSnapshot
and nudge
* swarm/shed: add metrics to each shed db
* swarm/shed: push metrics prefix up
* swarm/shed: rename prefix to metricsPrefix
* swarm/shed: unexport Meter, remove Mutex for quit channel
* geth/core/eth: implement constantinople override flag
* les: implemnent constantinople override flag for les clients
* cmd/geth, eth, les: fix typo, move flag to experimentals
* Rejects peers that respond with a different hash for any of the passed in block numbers.
* Meant for emergency situations when the network forks unexpectedly.
* swarm/network: Hive - do not notify peer if discovery is disabled
* p2p/simulations: validate all connections on loading a snapshot
* p2p/simulations: track all connections in on snapshot loading
* p2p/simulations: add snapshotLoadTimeout variable
* p2p/simulations: ignore control events in snapshot load
* p2p/simulations: simplify event loop synchronization
* p2p/simulations: return already connected error from Load function
* p2p/simulations: log warning on snapshot loading disconnection
Until this commit, when sending an RPC request that called `NewEVM`, a blank `vm.Config`
would be taken so as to set some options, based on the default configuration. If some extra
configuration switches were passed to the blockchain, those would be ignored.
This PR adds a function to get the config from the blockchain, and this is what is now used
for RPC calls.
Some subsequent changes need to be made, see https://github.com/ethereum/go-ethereum/pull/17955#pullrequestreview-182237244
for the details of the discussion.