Fix command definition reference.
Expose client type property (class).

One of normal, pubsub or the (unsupported) slave class.
Expose lastsave property on server state.
Add lastsave command.
Implement rdb save on shutdown.
Save handles multiple databases.
Fix expiry logic on load.
0.1.57
Listen for save, update lastsave timestamp.
Add bgsave command.
0.1.58