Windows Phone 8 Implementation

Hi Chris,

Thanks for this awesome plugin! I needed a WP8 implementation of your plugin so i wrote it, i hope you like it?

For now there's no support for the stationairy feature because WP does not have a Significant changes API (or so). The debug sounds are also hard to implement but maybe i'll get to that in the future.

In the next 2-3 weeks i'll try to publish my app in te MS Marketplace in order to verify if MS accepts this kind of Background operations...