Clean-up and XML handling enhancement:

- XML helper functions always return objects by winstd::com_obj or winstd::bstr reference now to ensure proper release by caller
- get_element_value()/put_element_value() can optionally return reference to the XML object if required
- WinStd macros to simplify dplhandle<> and handle<> inherited classes reused by non-copyable classes

lib/TLS/include/Method.h

@@ -46,6 +46,8 @@ namespace eap
 {
     class method_tls : public method
     {
+        WINSTD_NONCOPYABLE(method_tls)
+
     public:
 #pragma pack(push)
 #pragma pack(1)