Merge branch 'fjl-rlp-size-validation' into develop

cmd/rlpdump/main.go

cmd/utils/cmd.go

core/types/transaction.go

eth/handler.go

p2p/discover/udp.go

p2p/message.go

p2p/peer_error.go

rlp/decode.go

rlp/decode_test.go

rlp/encode.go

rlp/typecache.go

whisper/envelope.go

whisper/peer.go