feature<Stashes>: supports clear all stashes

src/Resources/Locales/en_US.xaml

@@ -542,4 +542,5 @@
     <sys:String x:Key="Text.BadArchiveFile">Invalid path for archive file</sys:String>
     <sys:String x:Key="Text.Required">This field is required</sys:String>
     <sys:String x:Key="Text.ConfirmRemoveRepo">You are removing repository '{0}'. Are you sure to continue?</sys:String>
+    <sys:String x:Key="Text.ConfirmClearStashes">You are trying to clear all stashes. Are you sure to continue?</sys:String>
 </ResourceDictionary>

src/Resources/Locales/zh_CN.xaml

@@ -541,4 +541,5 @@
     <sys:String x:Key="Text.BadArchiveFile">非法的存档文件路径！</sys:String>
     <sys:String x:Key="Text.Required">内容未填写！</sys:String>
     <sys:String x:Key="Text.ConfirmRemoveRepo">正在将 '{0}' 从列表中移除，是否要继续？</sys:String>
+    <sys:String x:Key="Text.ConfirmClearStashes">您正在丢弃所有的贮藏，一经操作，无法回退，是否继续？</sys:String>
 </ResourceDictionary>

src/Views/Widgets/Stashes.xaml

@@ -26,25 +26,43 @@
             
             <!-- Stashes List Group -->
             <Border Grid.Row="0" BorderBrush="{DynamicResource Brush.Border0}" BorderThickness="0,0,0,1">
-                <StackPanel Orientation="Horizontal">
+                <Grid>
+                    <Grid.ColumnDefinitions>
+                        <ColumnDefinition Width="Auto"/>
+                        <ColumnDefinition Width="Auto"/>
+                        <ColumnDefinition Width="Auto"/>
+                        <ColumnDefinition Width="*"/>
+                        <ColumnDefinition Width="Auto"/>
+                    </Grid.ColumnDefinitions>
+
                     <Path
+                        Grid.Column="0"
                         Margin="4,0"
                         Width="12" Height="12"
                         Fill="{DynamicResource Brush.FG2}"
                         Data="{StaticResource Icon.Stashes}"/>
 
                     <TextBlock
+                        Grid.Column="1"
                         Margin="4,0,0,0"
                         Text="{DynamicResource Text.Stashes.Stashes}" 
                         Foreground="{DynamicResource Brush.FG2}" 
                         FontWeight="Bold"/>
 
                     <controls:Loading
+                        Grid.Column="2"
                         x:Name="waiting"
                         Width="12" Height="12"
                         Margin="8,0,0,0"
                         Visibility="Collapsed"/>
-                </StackPanel>
+
+                    <controls:IconButton
+                        Grid.Column="4"
+                        Click="ClearAll"
+                        Width="14" Height="14"
+                        Margin="8,0"
+                        Icon="{StaticResource Icon.Clear}"/>
+                </Grid>
             </Border>
             
             <!-- Stashes List -->

src/Views/Widgets/Stashes.xaml.cs

@@ -25,6 +25,30 @@ namespace SourceGit.Views.Widgets {
             changeList.ItemsSource = null;
         }
 
+        private void ClearAll(object sender, RoutedEventArgs e) {
+            var confirmDialog = new ConfirmDialog(
+                App.Text("Apply.Warn"),
+                App.Text("ConfirmClearStashes"),
+                async () => {
+                    waiting.Visibility = Visibility.Visible;
+                    waiting.IsAnimating = true;
+                    Models.Watcher.SetEnabled(repo, false);
+                    await Task.Run(() => {
+                        new Commands.Command() {
+                            Cwd = repo,
+                            Args = "stash clear",
+                        }.Exec();
+                    });
+                    Models.Watcher.SetEnabled(repo, true);
+                    waiting.Visibility = Visibility.Collapsed;
+                    waiting.IsAnimating = false;
+                });
+
+            confirmDialog.Owner = App.Current.MainWindow;
+            confirmDialog.ShowDialog();
+            e.Handled = true;
+        }
+
         private async void OnStashSelectionChanged(object sender, SelectionChangedEventArgs e) {
             changeList.ItemsSource = null;
             selected = null;