* Add documentation and error variants to Client

* Reexport missing reexports

* Fix proc macro

* Rework the Client to support multiple concurrent requests

* Restore proc-macro functionnality

* More work

* More work

* More work

* Even more work

* Subscriptions working

* Dix docs

* More test fix

* Add a SubscriptionsClosed server event

* Don't attempt to send back response if connection is closed

* Implement into_subscription

* Properly support params in rpc_api!

* Respond with invalid param in case of parsing error