PropertyCross implementation using OnsenUI.

Hi,

@ColinEberhardt Suggested adding OnsenUI to the PropertyCross site.

I've made a simple implementation of the PropertyCross application using OnsenUI.

I wasn't really sure how to submit the implementation so the pull request only contains the `www` folder. If you would like me to add something I will gladly do it.

It runnable by just serving the `www` folder.

OnsenUI works on Android 2.3+ and iOS6+ but not on Windows phones.