Add missing LightTheme for AvalonDock

ILSpy/themes/LightTheme.xaml

@@ -1,6 +1,9 @@
 <ResourceDictionary xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
                     xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
                     xmlns:styles="urn:TomsToolbox.Wpf.Styles">
+	<ResourceDictionary.MergedDictionaries>
+		<ResourceDictionary Source="/AvalonDock.Themes.VS2013;component/lighttheme.xaml" />
+	</ResourceDictionary.MergedDictionaries>
 	<SolidColorBrush x:Key="{x:Static SystemColors.ControlLightLightBrushKey}" Color="#FCFCFC" />
 	<SolidColorBrush x:Key="{x:Static SystemColors.ControlLightBrushKey}" Color="#D8D8E0" />
 	<SolidColorBrush x:Key="{x:Static SystemColors.ControlBrushKey}" Color="#F5F5F5" />