message: put tabs on a single line and add basic animation on change
diff: <Grid>
  <Frame
  Source="{Binding ContentPageSource, Mode=OneWay, Converter={app_ui_framework_valueconverters:TypePageConverter}}"
  - NavigationUIVisibility="Hidden" >
  - <i:Interaction.Triggers>
  - <i:EventTrigger EventName="Navigating">
  - <i:InvokeCommandAction Command="{Binding FrameNavigating}" />
  - </i:EventTrigger>
  - </i:Interaction.Triggers>
  - </Frame>
  + DataContext="{Binding }"
  + NavigationUIVisibility="Hidden" />
  <Grid Background="{DynamicResource MahApps.Brushes.Control.Background}" Visibility="{Binding ShowError, Converter={StaticResource BooleanToVisibilityConverter}}" HorizontalAlignment="Stretch" VerticalAlignment="Stretch">
  <StackPanel HorizontalAlignment="Center" VerticalAlignment="Center">
  <Viewbox Height="200" Stretch="Uniform">
  </ControlTemplate>
  </Setter.Value>
  </Setter>
  + <Setter Property="mah:ScrollViewerHelper.IsHorizontalScrollWheelEnabled" Value="True" />
  + <Setter Property="mah:TabControlHelper.Transition" Value="Left" />
  + <Style.Triggers>
  + <Trigger Property="TabStripPlacement" Value="Top">
  + <Setter Property="Template" Value="{StaticResource MahApps.Templates.TabControl.AnimatedSingleRow.Horizontal}" />
  + </Trigger>
  + <Trigger Property="TabStripPlacement" Value="Bottom">
  + <Setter Property="Template" Value="{StaticResource MahApps.Templates.TabControl.AnimatedSingleRow.Horizontal}" />
  + </Trigger>
  + <Trigger Property="TabStripPlacement" Value="Left">
  + <Setter Property="Template" Value="{StaticResource MahApps.Templates.TabControl.AnimatedSingleRow.Vertical}" />
  + </Trigger>
  + <Trigger Property="TabStripPlacement" Value="Right">
  + <Setter Property="Template" Value="{StaticResource MahApps.Templates.TabControl.AnimatedSingleRow.Vertical}" />
  + </Trigger>
  + </Style.Triggers>
  </Style>
  </TabControl.Style>
  </TabControl>
  