message: WIP password strength view (win)
diff: mah:TextBoxHelper.Watermark="Password"
  behaviours:PasswordBoxBindingBehavior.Password="{Binding Password, ValidatesOnDataErrors=True, NotifyOnValidationError=True}"
  behaviors:FocusHelper.IsFocused="{Binding IsPasswordFocused}"/>
  + <mah:CustomValidationPopup PlacementTarget="{Binding ElementName=passwordBox}"
  + Placement="Top"
  + IsOpen="{Binding ElementName=passwordBox, Path=IsKeyboardFocused, Mode=OneWay}"
  + AllowsTransparency="True">
  + <Grid Background="Transparent">
  + <Border Width="268"
  + Height="112"
  + BorderThickness="1"
  + BorderBrush="{DynamicResource Toggl.LightGrayBrush}"
  + Background="{DynamicResource Toggl.CardBackground}"
  + Margin="4 0 4 4">
  + <Border.Effect>
  + <DropShadowEffect Direction="270"
  + Opacity="0.1"
  + BlurRadius="4"
  + ShadowDepth="1" />
  + </Border.Effect>
  + <TextBlock Style="{StaticResource Toggl.CaptionText}"
  + Text="Please make sure your password includes:" />
  + </Border>
  + </Grid>
  + </mah:CustomValidationPopup>
  <Label HorizontalAlignment="Left"
  Margin="48 16 0 0"
  