feat: Document presence indicator (#1114)

* Update websockets to allow joining document-based rooms

* dynamic websocket joining

* emit user.join/leave events when entering and exiting document rooms

* presence storage

* feat: frontend presence store

* lint

* UI updates

* First pass editing state

* refactoring

* Timeout per user/doc
lint

* Document data loading refactor to keep Socket mounted

* restore: Mark as viewed functionality
Add display of 'you' to collaborators

* fix: Socket/document remount when document slug changes due to title change

* Revert unneccessary package update

* Move editing ping interval to a shared constant

* fix: Flash of sidebar when loading page directly on editing mode

* separate document and revision loading

* add comments for socket events

* fix: Socket events getting bound multiple times on reconnect

* fix: Clear client side presence state on disconnect

* fix: Don't ignore server side error
Improved documentation

* More comments / why comments

* rename Socket -> SocketPresence

* fix: Handle redis is down
remove unneccessary join

* fix: PR feedback

app/scenes/Document/components/HideSidebar.js

@@ -0,0 +1,24 @@
+// @flow
+import * as React from 'react';
+import UiStore from 'stores/UiStore';
+
+type Props = {
+  ui: UiStore,
+  children?: React.Node,
+};
+
+class HideSidebar extends React.Component<Props> {
+  componentDidMount() {
+    this.props.ui.enableEditMode();
+  }
+
+  componentWillUnmount() {
+    this.props.ui.disableEditMode();
+  }
+
+  render() {
+    return this.props.children || null;
+  }
+}
+
+export default HideSidebar;