- fix cluster (make logging message buffers omp local)
- add cluster test case 3

- fix logger race in omp threads
- add mpi to docker images

- remove redundant loop when reuniting outputs from all threads

- For safety, since some loops are murky, overallocate some arrays of size nspheres instead of configurations
- correct a race in the definition of myompthread
- add some omp barriers to force synchronisations