Code Cleanup

- Added declared but unimplemented copy constructors and assignment
  operators.

src/Sequence.h

@@ -39,6 +39,9 @@ public:
   Sequence (const std::string&);         // Parse
   ~Sequence ();                          // Destructor
 
+  Sequence (const Sequence&);
+  Sequence& operator= (const Sequence&);
+
   bool valid (const std::string&) const;
   void parse (const std::string&);
   void combine (const Sequence&);