ENH: fix std in kwsys, has to be kwsys_stl

Registry.cxx

@@ -267,7 +267,6 @@ bool Registry::DeleteValue(const char *subkey, const char *key)
     if ( !this->Open(this->GetTopLevel(), subkey, 
         Registry::READWRITE) )
       {
-      std::cerr << "Failed to open\n";
       return res;
       }
     open = true;

SystemTools.cxx

@@ -1923,7 +1923,7 @@ kwsys_stl::string SystemTools::FindProgram(
     {
     return "";
     }
-  std::string ext = SystemTools::GetExecutableExtension();
+  kwsys_stl::string ext = SystemTools::GetExecutableExtension();
   if(ext.size())
     {
     unsigned int len = strlen(name);