fix: use sender to carry data for chain related signals
fix: use sender to carry data for chain related signals

gsalgado/pyethapp,ethereum/pyethapp,RomanZacharia/pyethapp,RomanZacharia/pyethapp,danielnovy/test,kustomzone/pyethapp,changwu-tw/pyethapp,heikoheiko/pyethapp,changwu-tw/pyethapp,ethereum/pyethapp,vaporry/pyethapp,d-das/pyethapp,gsalgado/pyethapp