remove some xxx comments and the config.mempool.recheck_empty (#2505)

* remove some XXX

* config: remove Mempool.RecheckEmpty

* docs: remove recheck_empty

types/params.go

@@ -99,8 +99,6 @@ func (params ConsensusParams) Update(params2 *abci.ConsensusParams) ConsensusPar
 	}
 
 	// we must defensively consider any structs may be nil
-	// XXX: it's cast city over here. It's ok because we only do int32->int
-	// but still, watch it champ.
 	if params2.BlockSize != nil {
 		res.BlockSize.MaxBytes = params2.BlockSize.MaxBytes
 		res.BlockSize.MaxGas = params2.BlockSize.MaxGas

types/vote.go

@@ -61,8 +61,8 @@ func IsVoteTypeValid(type_ byte) bool {
 	}
 }
 
-// Address is hex bytes. TODO: crypto.Address
-type Address = cmn.HexBytes
+// Address is hex bytes.
+type Address = crypto.Address
 
 // Represents a prevote, precommit, or commit vote from validators for consensus.
 type Vote struct {