themed scroll bars, rounded courners, libmpv update

src/WPF/ConfWindow.xaml

@@ -57,7 +57,17 @@
                 Foreground="{Binding Theme.Heading}"
                 Background="{Binding Theme.Background}"
                 >
-                
+
+                <ListBox.ItemContainerStyle>
+                    <Style TargetType="ListBoxItem">
+                        <Style.Resources>
+                            <Style TargetType="Border">
+                                <Setter Property="CornerRadius" Value="3"/>
+                            </Style>
+                        </Style.Resources>
+                    </Style>
+                </ListBox.ItemContainerStyle>
+
                 <ListBox.ItemTemplate>
                     <DataTemplate>
                         <TextBlock Text="{Binding}" FontSize="16" />