A test for a Property wich could not be found on WindowClone!
But we should throw a Exception that the Property is not writeable!
Better Error MEssage -> Show wich Property is doubled
XAML Designer Sample -> Better Error Display
Fixes that sometimes both namespaces need to be compared.

This XAML works after this fix:

<Fluent:RibbonWindow RenderOptions.BitmapScalingMode="HighQuality"
        xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
        xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
        xmlns:windows="clr-namespace:MCC.Visu.Configurator.Windows"
                    xmlns:Fluent="clr-namespace:Fluent;assembly=Fluent"
                    >
    <Grid>
            <Fluent:Ribbon >
                <Fluent:RibbonTabItem>
	 <Fluent:RibbonGroupBox>
                            <Fluent:Gallery>
                                <Fluent:Gallery.ItemContainerStyle>
                                    <Style />
                                </Fluent:Gallery.ItemContainerStyle>
                                <Image />
                            </Fluent:Gallery>
                 </Fluent:RibbonGroupBox>
                </Fluent:RibbonTabItem>
                </Fluent:Ribbon>
          </Grid>
</Fluent:RibbonWindow>
Xaml Parser should use the current node on Exceptions, so we have a better Line/Column Number
Outline Node Can throw an Exception when there is a Binding on this Properties.
This fixes it!