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/DropToImport.js

@@ -52,7 +52,7 @@ class DropToImport extends React.Component<Props> {
       if (documentId && !collectionId) {
         const document = await this.props.documents.fetch(documentId);
         invariant(document, 'Document not available');
-        collectionId = document.collection.id;
+        collectionId = document.collectionId;
       }
 
       for (const file of files) {