ZanRedisDB Versions Save

• speedup and fix snapshot recovery
• avoid leader transfer while applying the snapshot
• avoid transfer snapshot while not in sync only mode

1. more configuration for rocksdb
2. new api for range delete and range compaction
3. optimize performance for range query.
4. fix leader restore crash while syncing from remote cluster
5. some fix on the cross cluster syncer.

1. support geohash, hyperloglog, json
2. support rackaware
3. support sync in async mode between data centers

First release. Support most of the redis command: KV, HASH, LIST, SET, ZSET