Commented Issue: RangeSlider DataBinding [21135]

Hi,

I have a RangeSlider in a DataTemplate. The Binding to LowerValue and HigherValue does not work correctly.

```
<DataTemplate DataType="{x:Type vm:NumericFilter}">
<Grid>
<Grid.RowDefinitions>
<RowDefinition Height="Auto" />
<RowDefinition Height="Auto" />
</Grid.RowDefinitions>
<TextBox x:Name="tbSelectedMin"
Text="{Binding Path=SelectedMin}"
HorizontalAlignment="Left" />
<Button Content="Reset"
Command="{Binding Path=ResetCommand}"
HorizontalAlignment="Center" />
<TextBox x:Name="tbSelctedMax"
Text="{Binding Path=SelectedMax}"
HorizontalAlignment="Right" />
<xctk:RangeSlider x:Name="rsRange"
Grid.Row="1"
Minimum="{Binding Path=Min}"
Maximum="{Binding Path=Max}"
HigherValue="{Binding Path=SelectedMax, Mode=TwoWay, UpdateSourceTrigger=PropertyChanged}"
LowerValue="{Binding Path=SelectedMin,
Mode=TwoWay,
UpdateSourceTrigger=PropertyChanged}" />
</Grid>
</DataTemplate>
```

while "normal" sliders work as expected:
```
<StackPanel Grid.Row="1">
<Slider Minimum="{Binding Path=Min}"
Maximum="{Binding Path=Max}"
Value="{Binding Path=SelectedMin, Mode=TwoWay, UpdateSourceTrigger=PropertyChanged}"/>
<Slider Minimum="{Binding Path=Min}"
Maximum="{Binding Path=Max}"
Value="{Binding Path=SelectedMax, Mode=TwoWay, UpdateSourceTrigger=PropertyChanged}" />
</StackPanel>
```
Comments: ** Comment from web user: emartin **

Also fixed for the range slider in the next version:
- Keyboard navigation (focus)
When displayed vertically:
- Width of the RangeSlider when displayed vertical is no longer forced to 50, but resized to fit to its natural width, just like any other controls