First crack at PhoneGap for Windows Phone 7.

No device functionality yet (the API is super new), but from my brief overview, it looks like at least initially
we should be able to get network status, vibrate and accelerometer functionality... although none of these
are testable via the emulator.

Basically we load local assets from the www folder into a WebBrowser control, and using the InvokeScript
and window.external.Notify functions to pass messages between the browser and the .NET code-behind.

todo:
- add some device functionality
- figure out how to load local, relatively-referenced assets from the html pages etc. so that the assets load properly.