+* Implement rehashing and cluster check in redis-trib.
+* Reimplement MIGRATE / RESTORE to use just in memory buffers (no disk at
+ all). This will require touching a lot of the RDB stuff around, but we may
+ hand with faster persistence for RDB.
+* Implement the slave nodes semantics and election.
+* Allow redis-trib to create a cluster-wide snapshot (using SYNC).
+* Allow redis-trib to restore a cluster-wide snapshot (implement UPLOAD?).