Merge pull request #3037 from karalabe/state-caching

accounts/abi/bind/backends/simulated.go

core/blockchain.go

core/chain_makers_test.go

core/state/dump.go

core/state/managed_state.go

core/state/managed_state_test.go

core/state/state_object.go

core/state/state_test.go

core/state/statedb.go

core/vm/environment.go

core/vm/instructions.go

eth/api.go

internal/ethapi/api.go

light/state_test.go

tests/state_test_util.go

tests/util.go

tests/vm_test_util.go