Websocket Support (#937)

* Atom / RSS meta link

* Spike

* Feeling good about this spike now

* Remove document.collection

* Remove koa.ctx from all presenters to make them portable outside requests

* Remove full serialized model from events
Move events.add to controllers for now, will eventually be in commands

* collections.create event
parentDocument -> parentDocumentId

* Fix up deprecated tests

* Fixed: Doc creation

* documents.move

* Handle collection deleted

* 💚

* Authorize room join requests

* Move starred data structure
Account for documents with no context on sockets

* Add socket.io-redis

* Add WEBSOCKETS_ENABLED env variable to disable websockets entirely for self hosted
New installations will default to true, existing installations to false

* 💚 No need for promise response here

* Reload notice

app/components/Sidebar/components/CollectionLink.js

@@ -65,6 +65,7 @@ class CollectionLink extends React.Component<Props> {
               <DocumentLink
                 key={document.id}
                 document={document}
+                collection={collection}
                 activeDocument={activeDocument}
                 prefetchDocument={prefetchDocument}
                 depth={1.5}