Added first tests for point_space.

dummys/MPI_dummy.py

keepers/nifty_configuration.py

lm/__init__.py

nifty_core.py

nifty_mpi_data.py

nifty_paradict.py

operators/nifty_explicit.py

operators/nifty_operators.py

rg/nifty_fft.py

rg/nifty_rg.py

test/test_nifty_mpi_data.py

test/test_nifty_point_space.py