Integration - Context::parse

- Integrated Att parsing.
- Unit tests are broken right now.
- Stubbed Context::shadow.
- Implemented Duration::valid.
- Task is broken right now.

src/Att.h

@@ -42,6 +42,7 @@ public:
   ~Att ();                                      // Destructor
 
   bool valid (const std::string&) const;
+  void parse (const std::string&);
   void parse (Nibbler&);
   bool validMod (const std::string&) const;
   bool match (const Att&) const;