Add back in old hybrid functions, needed by Kokkos package

  virtual bigint memory_usage();

  virtual bigint memory_usage_bonus() {return 0;}

  // old hybrid functions, needed by Kokkos package

  virtual int pack_comm_hybrid(int, int *, double *) {return 0;}

  virtual int unpack_comm_hybrid(int, int, double *) {return 0;}

  virtual int pack_reverse_hybrid(int, int, double *) {return 0;}

  virtual int unpack_reverse_hybrid(int, int *, double *) {return 0;}

  virtual int pack_border_hybrid(int, int *, double *) {return 0;}

  virtual int unpack_border_hybrid(int, int, double *) {return 0;}

  virtual int data_atom_hybrid(int, char **) {return 0;}

  virtual int data_vel_hybrid(int, char **) {return 0;}

  virtual int pack_data_hybrid(int, double *) {return 0;}

  virtual int write_data_hybrid(FILE *, double *) {return 0;}

  virtual int pack_vel_hybrid(int, double *) {return 0;}

  virtual int write_vel_hybrid(FILE *, double *) {return 0;}

 protected:

  int nmax;                    // local copy of atom->nmax

  int deform_vremap;           // local copy of domain properties