Merge pull request #1801 from fjl/ethdb

cmd/geth/blocktestcmd.go

cmd/geth/chaincmd.go

cmd/geth/js_test.go

cmd/utils/flags.go

common/natspec/natspec_e2e_test.go

core/bench_test.go

core/block_processor.go

core/chain_makers.go

core/chain_manager.go

core/chain_manager_test.go

core/chain_util.go

core/genesis.go

core/helper_test.go

core/manager.go

core/state/state_object.go

core/state/statedb.go

core/transaction_util.go

eth/backend.go

eth/handler.go

ethdb/database.go