Free Tmp MPI Group

a similar leak was discovered in the PS plugin
by @f-schmitt-zih short time ago
Valgrind Init Input Values, Copy, NoC++11

- .data() is C++11
- Valgrind sometimes complains about non-init OUTPUT parameters
  in mpi calls (exclude filters work only partially)
- update copyright
Merge pull request #433 from ax3l/fix-cuSTLReduceMPIGrpMemLeak

Fix cuSTL Reduce MPI Group Free