Added targets to update the XML docs post build with a language attribute.

AddXmlLanguage.targets

@@ -0,0 +1,65 @@
+<?xml version="1.0" encoding="utf-8"?>
+<Project xmlns="http://schemas.microsoft.com/developer/msbuild/2003">
+    <UsingTask TaskName="InjectXmlLanguage" TaskFactory="CodeTaskFactory" AssemblyFile="$(MSBuildToolsPath)\Microsoft.Build.Tasks.Core.dll">
+        <ParameterGroup>
+            <InputFiles ParameterType="Microsoft.Build.Framework.ITaskItem[]" Required="true" />
+        </ParameterGroup>
+        <Task>
+            <Reference Include="System" />
+            <Using Namespace="System.Diagnostics" />
+            <Using Namespace="System.IO" />
+            <Code Type="Fragment" Language="cs">
+                <![CDATA[
+                    Log.LogMessage("Called InjectXmlLanguage");
+                    foreach (var inputFilePath in InputFiles.Select(f => f.ItemSpec))
+                    {
+                        Log.LogMessage("Fixing {0}", inputFilePath);
+                        string filePath = inputFilePath;
+                        if (filePath.EndsWith(".dll", StringComparison.OrdinalIgnoreCase))
+                        {
+                            filePath = filePath.Substring(0, filePath.Length - 3) + "xml";
+                        }
+
+                        if (filePath.EndsWith(".xml", StringComparison.OrdinalIgnoreCase))
+                        {
+                            string[] files = null;
+                            int starIndex = filePath.IndexOf('*');
+                            if (starIndex >= 0)
+                            {
+                                //string[] directories = Directory.GetDirectories("");
+                                //string[] files = Directory.GetFiles(Path.GetDirectoryName(filePath));
+                                string dir = filePath.Substring(0, starIndex);
+                                if (string.IsNullOrEmpty(dir))
+                                {
+                                    dir = ".";
+                                }
+
+                                string file = Path.GetFileName(filePath.Substring(starIndex));
+                                files = Directory.GetFiles(dir, file, SearchOption.AllDirectories);
+                            }
+                            else
+                            {
+                                files = new[] { filePath };
+                            }
+
+                            foreach (string fileName in files)
+                            {
+                                if (File.Exists(fileName))
+                                {
+                                    Log.LogMessage("Processing XML: {0}", fileName);
+                                    string text = File.ReadAllText(fileName);
+                                    text = text.Replace("<doc>", "<doc xml:lang=\"en\">");
+                                    File.WriteAllText(fileName, text);
+                                }
+                            }
+                        }
+                    }
+                ]]>
+            </Code>
+        </Task>
+    </UsingTask>
+
+    <Target Name="FixXmlDocumentation" AfterTargets="AfterBuild" DependsOnTargets="AfterBuild">
+        <InjectXmlLanguage InputFiles="$(DocumentationFile)" />
+    </Target>
+</Project>

Common.targets

@@ -2,5 +2,6 @@
 <Project xmlns="http://schemas.microsoft.com/developer/msbuild/2003">
 
   <Import Project="Signing.targets" />
+  <Import Project="AddXmlLanguage.targets" />
 
 </Project>