COMMON: Make connections and users container

[seitbekir]

Server need a connections and users container, to make it possible for horizontal scalins, making subscriptions plugins and ability to send messages to other connections.

Part that will store and share connections and users by id is Adapter.

• Create EventEmitter based Adapter (use by default)
• Create RedisEventEmitter based Adapter

Needs to add functions to push messages to clients.

• Create plugin for client-side routing.