Make track changes a feature flag

services/web/app/coffee/controllers/ProjectController.coffee

@@ -120,7 +120,7 @@ module.exports = class ProjectController
 									allowed: true
 							featureSwitches:
 								dropbox: false
-								longPolling: false
+								trackChanges: false
 					else
 						anonymous = false
 					SubscriptionLocator.getUsersSubscription user._id, (err, subscription)->
@@ -154,7 +154,7 @@ module.exports = class ProjectController
 										spellCheckLanguage: user.ace.spellCheckLanguage
 										pdfViewer : user.ace.pdfViewer
 										docPositions: {}
-										longPolling: user.featureSwitches.longPolling
+										trackChanges: user.featureSwitches.trackChanges
 									})
 									sharelatexObject : JSON.stringify({
 										siteUrl: Settings.siteUrl,

services/web/app/coffee/models/User.coffee

@@ -32,7 +32,7 @@ UserSchema = new Schema
 						}
 	featureSwitches	  : {
 							dropbox: {type:Boolean, default:true},
-							longPolling: {type:Boolean, default:false}
+							trackChanges: {type:Boolean, default:false}
 						}
 	referal_id : {type:String, default:() -> uuid.v4().split("-")[0]}
 	refered_users: [ type:ObjectId, ref:'User' ]

services/web/public/coffee/ide.coffee

@@ -97,8 +97,6 @@ define [
 			ioOptions =
 				reconnect: false
 				"force new connection": true
-			if @userSettings.longPolling
-				ioOptions.transports = ["xhr-polling"]
 			@socket = socket = io.connect null, ioOptions
 
 			@messageManager = new MessageManager(@)
@@ -119,7 +117,8 @@ define [
 			@cursorManager = new CursorManager(@)
 			@fileViewManager = new FileViewManager(@)
 			@analyticsManager = new AnalyticsManager(@)
-			@trackChangesManager = new TrackChangesManager(@)
+			if @userSettings.trackChanges
+				@trackChangesManager = new TrackChangesManager(@)
 
 			@setLoadingMessage("Connecting")
 			firstConnect = true