Moved application code to the Application layer

Imported Win10 project
Code cleanup
WIP - Use common UWP services for Win8.1 and Win10

ModernKeePass10/Views/MainPageFrames/SaveDatabasePage.xaml.cs

@@ -0,0 +1,57 @@
+using System;
+using System.Collections.Generic;
+using Windows.Storage.AccessCache;
+using Windows.Storage.Pickers;
+using Windows.UI.Xaml;
+using Windows.UI.Xaml.Controls;
+using Windows.UI.Xaml.Navigation;
+using ModernKeePass.ViewModels;
+
+// The Blank Page item template is documented at http://go.microsoft.com/fwlink/?LinkId=234238
+
+namespace ModernKeePass.Views
+{
+    /// <summary>
+    /// An empty page that can be used on its own or navigated to within a Frame.
+    /// </summary>
+    public sealed partial class SaveDatabasePage
+    {
+        private Frame _mainFrame;
+        public SaveViewModel ViewModel { get; }
+        public SaveDatabasePage()
+        {
+            InitializeComponent();
+            ViewModel = new SaveViewModel();
+        }
+
+        protected override void OnNavigatedTo(NavigationEventArgs e)
+        {
+            base.OnNavigatedTo(e);
+            _mainFrame = e.Parameter as Frame;
+        }
+
+        private void SaveButton_OnClick(object sender, RoutedEventArgs e)
+        {
+            ViewModel.Save();
+            _mainFrame.Navigate(typeof(MainPage10));
+        }
+
+        private async void SaveAsButton_OnClick(object sender, RoutedEventArgs e)
+        {
+            var savePicker = new FileSavePicker
+            {
+                SuggestedStartLocation = PickerLocationId.DocumentsLibrary,
+                SuggestedFileName = "New Database"
+            };
+            savePicker.FileTypeChoices.Add("KeePass 2.x database", new List<string> { ".kdbx" });
+
+            var file = await savePicker.PickSaveFileAsync();
+            if (file == null) return;
+
+            var token = StorageApplicationPermissions.FutureAccessList.Add(file);
+            ViewModel.Save(token);
+
+            _mainFrame.Navigate(typeof(MainPage10));
+        }
+    }
+}