block.to_dct make  state and txs optional
block.to_dct make  state and txs optional

pipermerriam/pyethereum,ethers/pyethereum,shahankhatch/pyethereum,ckeenan/pyethereum,holiman/pyethereum,ethereum/pyethereum,ddworken/pyethereum,vaporry/pyethereum,karlfloersch/pyethereum,pipermerriam/pyethereum,jnnk/pyethereum,harlantwood/pyethereum,inzem77/pyethereum,ethermarket/pyethereum,karlfloersch/pyethereum,shahankhatch/pyethereum,ethereum/pyethereum