GitLab

Misc changes. Separation of field and space functionalities further improved. The fft of a field now runs purely with a distributed data object as it is now the natural data object of rg_space.

Added a mpi_dummy.py. Integrated the paradicts to the spaces. Implemented unary_operation, binary_operation and norm in the spaces. Extended the functions of the distributed_data_object for the unary and binary operations.