adapt chain_manager to eth protocol interface

- add Status() to return td, currentblock hash, genesis hash
- GetChainHashesFromHash -> GetBlockHashesFromHash

core/chain_manager.go

@@ -137,6 +137,10 @@ func (bc *ChainManager) NewBlock(coinbase []byte) *types.Block {
 	return block
 }
 
+func (self *ChainManager) Status() (td *big.Int, currentBlock []byte, genesisBlock []byte) {
+	return self.TD, self.CurrentBlock.Hash(), self.Genesis().Hash()
+}
+
 func (bc *ChainManager) Reset() {
 	AddTestNetFunds(bc.genesisBlock)