* Rework the Client to support multiple concurrent requests

* Restore proc-macro functionnality

* More work

* More work

* Work on the Server subscriptions system

* More work on design

* More work

* More work

* Even more work

* Subscriptions working

* Dix docs

* More test fix

* Fix server-sent subscription notifications

* Add some server tests

* Subscriptions pending system working

* Remove TODO from tests

* Implement close() correctly

* Add comment on close()

* Fix proc macro

* Fix doctest

* Fix local doctest

* 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

* Fix compilation

* More fixing

* I'm getting tired of semver

* Add a SubscriptionsClosed server event

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

* Implement into_subscription

* Refactor RawServer to return RawServerEvent

* Fix docs

* Wrap common::Notification around

* Rename ServerRequestParams to Params

* Fix tests

* Rename local to local_raw and add tests for rpc_api!

* Add the tests

* Fix doctests

* Fix doctests

* Properly support params in rpc_api!

* Respond with invalid param in case of parsing error

* RawServer::supports_resuming now returns a Result

* Add a local client/server

* Fix build and docs

* Fix doctest