VS: Add Certificates to .vcxproj files

After certificates were moved into their own category in
cmGeneratorTarget, that category was not added for output by the VS 10
generator.  Add it now.

Source/cmVisualStudio10TargetGenerator.cxx

@@ -1330,6 +1330,10 @@ void cmVisualStudio10TargetGenerator::WriteAllSources()
   this->GeneratorTarget->GetAppManifest(manifestSources, "");
   this->WriteSources("AppxManifest", manifestSources);
 
+  std::vector<cmSourceFile const*> certificateSources;
+  this->GeneratorTarget->GetCertificates(certificateSources, "");
+  this->WriteSources("None", certificateSources);
+
   std::vector<cmSourceFile const*> externalObjects;
   this->GeneratorTarget->GetExternalObjects(externalObjects, "");
   for(std::vector<cmSourceFile const*>::iterator