Destroy XMLReader object attached to Reader one when this one is gone as to avoid

potential memory leaks.

src/Base/Reader.h

@@ -295,6 +295,7 @@ class BaseExport Reader : public std::istream
 {
 public:
     Reader(std::istream&, const std::string&, int version);
+    ~Reader();
     std::istream& getStream();
     std::string getFileName() const;
     int getFileVersion() const;