Merge pull request #2914 from fjl/node-coinhabit

cmd/geth/chaincmd.go

cmd/geth/consolecmd.go

cmd/geth/dao_test.go

cmd/geth/main.go

cmd/geth/monitorcmd.go

cmd/gethrpctest/main.go

cmd/utils/customflags.go

cmd/utils/flags.go

common/path.go

ethdb/database.go

node/api.go

node/config.go

node/config_test.go

node/defaults.go

node/doc.go

node/node.go

node/service.go

node/service_test.go

p2p/nat/nat.go