* added SFTP support

* Fixed bug with reference URL fields (for SearchURL)
* check for ART and display warning

src/Kp2aBusinessLogic/Io/SftpFileStorage.cs

@@ -0,0 +1,18 @@
+using Android.Content;
+#if !EXCLUDE_JAVAFILESTORAGE
+
+namespace keepass2android.Io
+{
+	public class SftpFileStorage: JavaFileStorage
+	{
+		public SftpFileStorage(IKp2aApp app) :
+			base(new Keepass2android.Javafilestorage.SftpStorage(), app)
+		{
+		}
+
+		
+	}
+
+	
+}
+#endif