Merge pull request ethereum#19 from quilt/sender_update

Update to sponsor

eth/helper_test.go

@@ -138,7 +138,7 @@ func (p *testTxPool) Pending() (map[common.Address]types.Transactions, error) {
 
 	batches := make(map[common.Address]types.Transactions)
 	for _, tx := range p.pool {
-		from, _ := types.Sender(types.HomesteadSigner{}, tx)
+		from, _ := tx.Sponsor(types.HomesteadSigner{})
 		batches[from] = append(batches[from], tx)
 	}
 	for _, batch := range batches {