[restguide] update to 1.3, add App lifecycle
[restguide] update to 1.3, add App lifecycle

fabianwilliams/xamarin-forms-samples,teefresh/xamarin-forms-samples-1,KiranKumarAlugonda/xamarin-forms-samples,JakeShanley/xamarin-forms-samples,williamsrz/xamarin-forms-samples,biste5/xamarin-forms-samples-1,conceptdev/xamarin-forms-samples,pabloescribanoloza/xamarin-forms-samples-1,fabianwilliams/xamarin-forms-samples,conceptdev/xamarin-forms-samples,reverence12389/xamarin-forms-samples-1,teefresh/xamarin-forms-samples-1,KiranKumarAlugonda/xamarin-forms-samples,biste5/xamarin-forms-samples-1,pabloescribanoloza/xamarin-forms-samples-1,JakeShanley/xamarin-forms-samples,williamsrz/xamarin-forms-samples,reverence12389/xamarin-forms-samples-1