Remove unused and unresolved ControlzEx namespace (#2191)

Author: greuelpirat

MaterialDesignThemes.Wpf/Themes/MaterialDesignTheme.DataGrid.xaml

@@ -1,8 +1,7 @@
 <ResourceDictionary xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
                     xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
                     xmlns:wpf="clr-namespace:MaterialDesignThemes.Wpf"
-                    xmlns:converters="clr-namespace:MaterialDesignThemes.Wpf.Converters"
-                    xmlns:controlzEx="clr-namespace:ControlzEx">
+                    xmlns:converters="clr-namespace:MaterialDesignThemes.Wpf.Converters">
 
     <ResourceDictionary.MergedDictionaries>
         <ResourceDictionary Source="pack://application:,,,/MaterialDesignThemes.Wpf;component/Themes/MaterialDesignTheme.CheckBox.xaml" />

MaterialDesignThemes.Wpf/Themes/MaterialDesignTheme.PopupBox.xaml

@@ -1,8 +1,7 @@
 <ResourceDictionary xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
                     xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
                     xmlns:wpf="clr-namespace:MaterialDesignThemes.Wpf"
-                    xmlns:converters="clr-namespace:MaterialDesignThemes.Wpf.Converters"
-                    xmlns:controlzEx="clr-namespace:ControlzEx">
+                    xmlns:converters="clr-namespace:MaterialDesignThemes.Wpf.Converters">
 
     <ResourceDictionary.MergedDictionaries>
         <ResourceDictionary Source="pack://application:,,,/MaterialDesignThemes.Wpf;component/Themes/MaterialDesignTheme.Button.xaml" />

MaterialDesignThemes.Wpf/Themes/MaterialDesignTheme.ValidationErrorTemplate.xaml

@@ -1,7 +1,6 @@
 <ResourceDictionary xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
                     xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
-                    xmlns:wpf="clr-namespace:MaterialDesignThemes.Wpf"
-                    xmlns:controlzEx="clr-namespace:ControlzEx">
+                    xmlns:wpf="clr-namespace:MaterialDesignThemes.Wpf">
     <BooleanToVisibilityConverter x:Key="BooleanToVisibilityConverter" />
 
     <ControlTemplate x:Key="MaterialDesignValidationErrorTemplate">