Added the class Parameter

Parameter is used to represents any type-based Parameter.

core/Parameter.h

+#ifndef EIIMAGE_PARAMETER_H
+#define EIIMAGE_PARAMETER_H
+
+#include <string>
+
+#include "Input.h"
+
+class Operation;
+
+template<typename T>
+class Parameter : public Input {
+  public:
+    
+    Parameter(std::string name, T* ptr = NULL) : _ptr(ptr), _name(name) {}
+    virtual Parameter<T>* clone() const = 0;
+  
+  protected:
+    T* _ptr;
+    std::string _name;
+    
+    friend class Operation;
+  
+};
+
+#endif //!EIIMAGE_PARAMETER_H
\ No newline at end of file