and added plot method in all spaces, to be implemented
Signed-off-by: Mihai Baltac <mbaltac@mpa-garching.mpg.de>

Fixed a few small bugs.

Fixed several bugs.

Added keyword arguments mean and std to Field.power_synthesize. Bug fixes in Field, SmoothingOperator, LMSpace and Space.

Removed NIFTy 2 files that have not been ported so far.

-> A Field on a PowerSpace can now be initialized with a spectral function.

- Refactor _smooth_helper
- Remove inplace property
- Rename method compute_k_array to distance_array in RGSpace
- Fix compute_k_array usage

Modified power_analyze in Field for complex power spectra.

Reordered methods in space classes.
Made Space.weight to an abc.abstractmethod.

- Remove smooth from abstract Space class
- Remove smooth from RGSpace
- Remove smooth and transform from HPSpace
- Move all HPSpace specific attributes to paradict

Adapted imports and setup.py to changes.