properly set up pair style quip for hybrid and hybrid/overlay

  if (!allocated) allocate();

  int n = atom->ntypes;

  // ensure I,J args are * *

   for (int i = 1; i <= n; i++){

      for (int j = 1; j <= n; j++) {

         setflag[i][j] = 1;

      }

   }

  if (narg != (4+n)) {

    char str[1024];

    sprintf(str,"Number of arguments %d is not correct, it should be %d", narg, 4+n);

    error->all(FLERR,str);

  }

  // ensure I,J args are * *

  if (strcmp(arg[0],"*") != 0 || strcmp(arg[1],"*") != 0)

    error->all(FLERR,"Incorrect args for pair coefficients");

  strcpy(quip_string,arg[3]);

  for (int i = 4; i < narg; i++) {

      if (0 == sscanf(arg[i],"%d",&map[i-4])) {

         char str[1024];

         sprintf(str,"Incorrect atomic number %s at position %d",arg[i],i);

         error->all(FLERR,str);

    if (strcmp(arg[i],"NULL") == 0)

      map[i-3] = -1;

    else

      map[i-3] = force->inumeric(FLERR,arg[i]);

  }

  // clear setflag since coeff() called once with I,J = * *

  n = atom->ntypes;

  for (int i = 1; i <= n; i++)

    for (int j = i; j <= n; j++)

      setflag[i][j] = 0;

  // set setflag i,j for type pairs where both are mapped to elements

  int count = 0;

  for (int i = 1; i <= n; i++)

    for (int j = i; j <= n; j++)

      if (map[i] >= 0 && map[j] >= 0) {

        setflag[i][j] = 1;

        count++;

      }

  if (count == 0) error->all(FLERR,"Incorrect args for pair coefficients");

  // Initialise potential

  // First call initialises potential via the fortran code in memory, and returns the necessary size

  // of quip_potential. This behaviour is invoked by setting n_potential_quip to 0.