use block_by_number index to tag and detect blocks in the canonical chain
use block_by_number index to tag and detect blocks in the canonical chain

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