Added WP8 support

www/screenorientation.wp8.js

@@ -0,0 +1,8 @@
+var exec = require('cordova/exec'),
+    screenOrientation = {};
+
+screenOrientation.setOrientation = function(orientation) {
+    exec(null, null, "YoikScreenOrientation", "screenOrientation", [orientation]);
+};
+
+module.exports = screenOrientation;