added Result copy constructor

libnfc_cpptools/inc/libnfc_cpptools/Result.h

 {
 public:
     Result();
+    Result(const Result<T>& other);
 
     static const Result<T> ok(const T& data);
     static const Result<T> strerror();
 {
 }
 
+template<class T>
+Result<T>::Result(const Result<T>& other)
+        : _data(other._data)
+        , _success(other._success)
+        , _error(other._error)
+{
+}
+
 template<class T>
 const Result<T> Result<T>::ok(const T& data)
 {