Merge pull request #8 from lindydonna/windows-offline

Add Windows Universal offline sample
Merge pull request #9 from lindydonna/xamarin-android

Add Xamarin.Android offline sample
Allow viewing completed items with incremental sync against completed items
Merge pull request #11 from wesmc7777/master

Allow viewing completed items with incremental sync against completed it...
Merge pull request #10 from lindydonna/master

Add Xamarin.iOS offline sample