Add some more XAML control template goodness.

samples/XamlTestApplicationPcl/XamlTestApp.paml

@@ -15,7 +15,10 @@
                   Background="{TemplateBinding Background}"
                   BorderBrush="{TemplateBinding BorderBrush}"
                   BorderThickness="{TemplateBinding BorderThickness}">
-            <ContentPresenter Content="{TemplateBinding Content}"/>
+            <ContentPresenter Content="{TemplateBinding Content}"
+                              TextBlock.Foreground="{TemplateBinding Foreground}"
+                              HorizontalAlignment="{TemplateBinding HorizontalContentAlignment}"
+                              VerticalAlignment="{TemplateBinding VerticalContentAlignment}"/>
           </Border>
         </ControlTemplate>
       </Setter>

src/Markup/Perspex.Markup.Xaml/Binding/XamlTemplateBinding.cs

@@ -45,7 +45,7 @@ namespace Perspex.Markup.Xaml.Binding
             if (sourceProperty == null)
             {
                 throw new InvalidOperationException(
-                    $"The property {SourcePropertyPath} could not be found on {instance.GetType()}.");
+                    $"The property {SourcePropertyPath} could not be found on {templatedParent.GetType()}.");
             }
 
             instance.Bind(targetProperty, templatedParent.GetObservable(sourceProperty), BindingPriority.Style);

src/Markup/Perspex.Markup.Xaml/OmniXAML

@@ -1 +1 @@
-Subproject commit 2a6309a4d9b60b848241a34bf2adfa16b52c7a85
+Subproject commit 4b0aeccf9ad094782973cd76f5319e8a2d600223

src/Perspex.Base/PerspexObjectExtensions.cs

@@ -77,8 +77,17 @@ namespace Perspex
 
             if (parts.Length == 1)
             {
-                return o.GetRegisteredProperties()
+                var result =  o.GetRegisteredProperties()
                     .FirstOrDefault(x => !x.IsAttached && x.Name == parts[0]);
+
+                if (result != null)
+                {
+                    return result;
+                }
+
+                // A type can .AddOwner an attached property.
+                return o.GetRegisteredProperties()
+                    .FirstOrDefault(x => x.Name == parts[0]);
             }
             else
             {