Made the steepest descent work.

Conflicts:
	nifty_mpi_data.py

propagator_operator still not working to full extend.

Removed nrow, ncol, ndim from operator class.
Made a tomography demo.
Fixed hashing of spaces and fft cache.
Fixed two bugs in the los_response line_integrator.

Fixed allreduce and Allreduce in MPI_dummy.py.
Added Option to d2o to skip the parsing of the input parameters. Added cumsum function to d2o.

Started working on the los response operator.
Switched off a sanity check in the d2o slicingdistributor's advanced indexing routine, because it was extremely slow (assert: is the first dimension ordered?).

Fixed zero-centering mask for even dimensions.

Some bugfixes.

Fixed a bug in nifty_mpi_data.

Many bugfixes and new tests for rg_space.
Fixed imp part of dependency_injector.

Added more space tests.
Fixed and improved the random number generator machinery.

Abstracted the power_indices class from rg_space -> Implemented a lm_power_indices class.
In the middle of space-interface cleaning.

Resorted the packages and the import structure.

Removed trailing whitespaces in nifty_operators.py

-> Many bugfixes and refactorings.