message: context menu border and separator color, separator width (win)
diff: <Style x:Key="{x:Static MenuItem.SeparatorStyleKey}" TargetType="{x:Type Separator}">
  <Setter Property="Background" Value="{DynamicResource Toggl.CardBackground}" />
  <Setter Property="IsTabStop" Value="False" />
  - <Setter Property="Margin" Value="8 2 8 2" />
  + <Setter Property="Margin" Value="0 2" />
  <Setter Property="SnapsToDevicePixels" Value="True" />
  <Setter Property="Template">
  <Setter.Value>
  <Grid Margin="0 2 0 0" SnapsToDevicePixels="{TemplateBinding SnapsToDevicePixels}">
  <Rectangle Height="1"
  Margin="0 0 0 1"
  - Fill="{DynamicResource Toggl.HoverElementBrush}"
  + Fill="{DynamicResource Toggl.LightGrayBrush}"
  SnapsToDevicePixels="{TemplateBinding SnapsToDevicePixels}"
  UseLayoutRounding="True" />
  <Rectangle Height="1"
  <Style TargetType="ContextMenu" BasedOn="{StaticResource MahApps.Styles.ContextMenu}">
  <Setter Property="Background" Value="{DynamicResource Toggl.CardBackground}" />
  - <Setter Property="BorderBrush" Value="{DynamicResource Toggl.TextBox.MouseOverBorder}" />
  + <Setter Property="BorderBrush" Value="{DynamicResource Toggl.LightGrayBrush}" />
  <Setter Property="Foreground" Value="{DynamicResource Toggl.PrimaryTextBrush}" />
  <Setter Property="FontSize" Value="{StaticResource NormalFontSize}" />
  <Setter Property="Padding" Value="2 4 2 4" />
  