Add MPI_Get_library_version to STUBS library

/* ---------------------------------------------------------------------- */

/* return "LAMMPS MPI STUBS" as name of the library */

int MPI_Get_library_version(char *verison, int *resultlen)

{

  const char string[] = "LAMMPS MPI STUBS";

  int len;

  if (!version || !resultlen) return MPI_ERR_ARG;

  len = strlen(string);

  memcpy(version,string,len+1);

  *resultlen = len;

  return MPI_SUCCESS;

}

/* ---------------------------------------------------------------------- */

/* return "localhost" as name of the processor */

int MPI_Get_processor_name(char *name, int *resultlen)

#define MPI_IN_PLACE NULL

#define MPI_MAX_PROCESSOR_NAME 128

#define MPI_MAX_LIBRARY_VERSION_STRING 128

typedef void MPI_User_function(void *invec, void *inoutvec,

                               int *len, MPI_Datatype *datatype);

int MPI_Init(int *argc, char ***argv);

int MPI_Initialized(int *flag);

int MPI_Finalized(int *flag);

int MPI_Get_library_version(char *version, int *resultlen);

int MPI_Get_processor_name(char *name, int *resultlen);

int MPI_Get_version(int *major, int *minor);