implemented Nitro+ archives creation.

encryption not implemented yet.

ArcFormats/CreateNPAWidget.xaml.cs

@@ -0,0 +1,24 @@
+using System.Windows.Controls;
+using GameRes.Formats.NitroPlus;
+
+namespace GameRes.Formats.GUI
+{
+    /// <summary>
+    /// Interaction logic for CreateNPAWidget.xaml
+    /// </summary>
+    public partial class CreateNPAWidget : Grid
+    {
+        public CreateNPAWidget ()
+        {
+            InitializeComponent ();
+        }
+
+        private void Reset_Click (object sender, System.Windows.RoutedEventArgs e)
+        {
+            this.EncryptionWidget.Scheme.SelectedIndex = 0;
+            this.Key1Box.Text = NpaOpener.DefaultKey1.ToString ("X8");
+            this.Key2Box.Text = NpaOpener.DefaultKey2.ToString ("X8");
+            this.CompressContents.IsChecked = false;
+        }
+    }
+}