Merge branch 'feature/field_multiple_space' of gitlab.mpcdf.mpg.de:ift/NIFTy into feature/field_multiple_space

# Conflicts:
#	nifty/field.py

Modified power_analyze in Field for complex power spectra.

Fix normalization in FFTOperator



See merge request !24

Fixed a bug in fft_operator.
Fixed a inconsistency in GFFT interface.

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

Fixed violation of LSP for implemented keyword/property.

Merge branch 'feature/field_multiple_space' of gitlab.mpcdf.mpg.de:ift/NIFTy into feature/field_multiple_space

Moved unitary property to LinearOperator.

TransformationOperator



See merge request !23

- Add get_default_codomain function in utilities
- Move all transforms to a subfolder inside the fft_operator
- Correct weight method calls in transform method of each transformation

- Create skeleton for TransformationOperator
- Minor bug fixes in Field, FFTTransform and RGRGTransformations and
  __init__.py for endomorphic_operator

Restructured new operator classes -> Introduced endomorphic_operator.py in order to avoid violation of Liskov's SP for square- and diagonal operator.
Removed paradict from operators.
Added from_random as static method to Field.

Merge branch 'feature/field_multiple_space' of gitlab.mpcdf.mpg.de:ift/NIFTy into feature/field_multiple_space

Refactor spaces to match Space specification

Remove all functionality not provided by spaces from all the space classes. Also, move space-specific attributes to the paradicts.

See merge request !21

Fixed a lot of small bugs. Removed the plotting routines from most of the spaces.

Fixed furthermore:
- Let's undo the changes in the RGSpace.__init__ (see the comment on gitlab)
- The HPSpaceParadict still has `distances` in the list.
- HPSpace.copy: Is this method really necessary? The one from Space should be sufficient, right?
- HPSpace.total_volume is missing
- Unnecessary imports of `random`, `LMSpace`,... in hp_space.py
- I removed the plotting functionality from the space classes.
- GLSpace.copy should also not be necessary
- GLSpace.dim is missing
- GLSpace.vol should be called `total_volume`. Also its implementation is defect: there is no self.distances for GLSpace. The total volume is just 4*pi.
- Use nifty_utilities.cast_axis_to_tuple in order to sanitize `axes` input in GLSpace.weight
- typo in `new_shape = np.ones(x.shape)`

See merge request !22

Fixed furthermore:
- Let's undo the changes in the RGSpace.__init__ (see the comment on gitlab)
- The HPSpaceParadict still has `distances` in the list.
- HPSpace.copy: Is this method really necessary? The one from Space should be sufficient, right?
- HPSpace.total_volume is missing
- Unnecessary imports of `random`, `LMSpace`,... in hp_space.py
- I removed the plotting functionality from the space classes.
- GLSpace.copy should also not be necessary
- GLSpace.dim is missing
- GLSpace.vol should be called `total_volume`. Also its implementation is defect: there is no self.distances for GLSpace. The total volume is just 4*pi.
- Use nifty_utilities.cast_axis_to_tuple in order to sanitize `axes` input in GLSpace.weight
- typo in `new_shape = np.ones(x.shape)`

- Remove distances from HPSpace paradict
- Cleanup GLSpace and add weight method

- 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.