Add PNaCl support for VS addin.

visual_studio/NativeClientVSAddIn/NaCl.Build.CPPTasks/XamlParser.cs

 using System;
 using System.Collections.Generic;
 using System.Linq;
 using System.Text;
 using System.IO;
 
 using Microsoft.Build.Framework;
 using System.Xaml;
 using Microsoft.Build.Framework.XamlTypes;
 using Microsoft.Build.Utilities;
 
 namespace NaCl.Build.CPPTasks
 {
-    class XamlParser
+    public class XamlParser
     {
         public XamlParser(string path)
         {
             // load and store properties from xaml file
             m_parsedBuildRule = (Rule)XamlServices.Load(path);
 
             // NOTE:
             // There are MSBuild classes which support command line building,
             // argument switch encapsulation and more.  Code within VCToolTask,
             // a hidden interface, uses some these classes to generate command line
@@ skipping 141 matching lines @@
         } // class
 
         private Rule m_parsedBuildRule;
         private Dictionary<string, PropertyWrapper> ToolProperties { get; set; }
 
         // function mapping for easy property function calling
         private Dictionary<Type, Action<CommandLineBuilder, BaseProperty, string>> m_typeFunctionMap;
     } // XamlParser
 } // namespace NaCl.Build.CPPTasks