Really 64

- SubscriptionManager
- SubscribeAggregator
- ObjectSubscriber
- Replayer
- GorillaCenter new subsxription handling
- All the Gorilla wiring
- JSON parsing fix
- WIP of Unsubscribe handling
naming `evt` as `failed` is so general, especially that this event on `r`, so I suggest to rename this event to `subscription-canceled` as that what really happened