Cordova samples need the Whitelist plugin for XHR requests

[ggailey777]

It looks like you now need the Whitelist plugin to be able to make remote xhr requests to Mobile Services (or any remote URL), which is what the client does. I submitted a PR with the fix #10, but you probably will need the same fix in other samples that access mobile services or any other remote service using XHR, which is why I also opened this issue.