Removes some outdated notes about cross-origin controllers. Needs re-writing.
Removes some outdated notes about cross-origin controllers. Needs re-writing.

martinthomson/ServiceWorker,sole/NavigationController,zuzusik/ServiceWorker,slightlyoff/ServiceWorker,chadoliver/ServiceWorker,martinthomson/ServiceWorker,justinleoye/ServiceWorker,slightlyoff/ServiceWorker,sole/NavigationController,mkruisselbrink/ServiceWorker,zuzusik/ServiceWorker,karolklp/ServiceWorker,justinleoye/ServiceWorker,chadoliver/ServiceWorker,mkruisselbrink/ServiceWorker,martinthomson/ServiceWorker,chadoliver/ServiceWorker,karolklp/ServiceWorker,justinleoye/ServiceWorker,zuzusik/ServiceWorker,karolklp/ServiceWorker