make Plumed.cpp obsolete in USER-PLUMED code by inserting it into fix_plumed.cpp

#include "modify.h"

#include "pair.h"

/*

  Do not link plumed directly but rather do it at runtime

*/

#define __PLUMED_WRAPPER_LINK_RUNTIME 1

/*

  Make sure the inline C++ interface is not included here.

  Should not be necessary, but it doesn't hurt.

*/

#define __PLUMED_WRAPPER_CXX 0

/*

  Tell Plumed.h to emit the whole implementation

*/

#define __PLUMED_WRAPPER_IMPLEMENTATION 1

/*

  Emit fortran wrappers

*/

#define __PLUMED_WRAPPER_FORTRAN 1

#include "Plumed.h"

using namespace LAMMPS_NS;

using namespace PLMD;

using namespace FixConst;