SplitButton: prevented a style targeting type Button to change the margin of the SplitButton

Main/Source/ExtendedWPFToolkitSolution/Src/WPFToolkit.Extended/SplitButton/Themes/Generic.xaml

@@ -42,7 +42,7 @@
                                 <ColumnDefinition Width="*" />
                                 <ColumnDefinition Width="Auto" />
                             </Grid.ColumnDefinitions>
-                            <Button x:Name="PART_ActionButton" HorizontalContentAlignment="{TemplateBinding HorizontalContentAlignment}" VerticalContentAlignment="{TemplateBinding VerticalContentAlignment}" Padding="{TemplateBinding Padding}" >
+                            <Button x:Name="PART_ActionButton" Margin="0" HorizontalContentAlignment="{TemplateBinding HorizontalContentAlignment}" VerticalContentAlignment="{TemplateBinding VerticalContentAlignment}" Padding="{TemplateBinding Padding}" >
                                 <Button.Template>
                                     <ControlTemplate TargetType="Button">
                                         <ContentPresenter />