Put the step color widgets in a StackPanel.

Doing this in a separate commit since it changes a lot of indentation but
doesn't really change much code.

smx-config/MainWindow.xaml

@@ -664,17 +664,14 @@ Use if the platform is too sensitive.</clr:String>
 
                         <Separator Margin="0,10,0,4" />
 
-                        <TextBlock HorizontalAlignment="Center" Margin="0,15,0,0" VerticalAlignment="Top"
-                                   TextAlignment="Center"
-                                   xml:space="preserve" FontSize="16">Panel colors</TextBlock>
-
-                        <TextBlock DockPanel.Dock="Top" HorizontalAlignment="Center" Margin="0,15,0,10" VerticalAlignment="Top"
-                                   TextAlignment="Center"
-                                   xml:space="preserve"
->Set the color each arrow lights when pressed.</TextBlock>
+                        <StackPanel 
+                            Visibility="Visible"
+                            Name="ColorPickerGroup" HorizontalAlignment="Center" Orientation="Vertical">
+                            <TextBlock TextAlignment="Center">
+                                Set the color each arrow lights when pressed.
+                            </TextBlock>
 
                             <StackPanel HorizontalAlignment="Center" Orientation="Horizontal">
-                            
                                 <!-- The duplication here could be factored out, but with WPF it's not really worth it: -->
                                 <Grid x:Name="PanelColorP1" Background="#FFE5E5E5" Width="100" Height="100" HorizontalAlignment="Center" VerticalAlignment="Top">
                                     <controls:PanelColorButton Panel="0" Content="↖" Margin="-60,-50,0,0" SelectedPanel="{Binding Path=SelectedPanel, Mode=TwoWay, ElementName=AutoLightsColor}" />
@@ -712,6 +709,7 @@ Use if the platform is too sensitive.</clr:String>
 
                             <Button x:Name="SetAllPanelsToCurrentColor" Content="Set all panels to this color" HorizontalAlignment="Center" Padding="6,2" Margin="0,6,0,0" />
                         </StackPanel>
+                    </StackPanel>
 
                     <!-- This version label is tweaked so it's in the same place as the one on the
                          connecting screen.  If we use the same margin, the tab container's border