bump required cordova-wp8 version to 4.0.0
diff --git a/plugin.xml b/plugin.xml
index 0d2e168..c7955a9 100644
--- a/plugin.xml
+++ b/plugin.xml
@@ -31,6 +31,10 @@
 
     <!-- dependency id="org.apache.cordova.file@1" /-->
     <dependency id="cordova-plugin-file" version=">=2.0.0" />
+        
+    <engines>
+        <engine name="cordova-wp8" version="1.0.0" platform="android" scriptSrc="path_to_my_custom_framework_version"/>
+    </engines>
 
     <js-module src="www/FileTransferError.js" name="FileTransferError">
         <clobbers target="window.FileTransferError" />