- also remove one outdated unit test

- _MappingBase.dim -> _MappingBase.dims
- rework IntensityMap and gradient removal, the value of the delta has still to be given mannually (but should come from the range of the unique values)
- add testFullSteam to check the full treatment without GUI
- rework DimensionGUI to display if asked the unique values for each dimensions once fit has been done

- now OverwritingOperation can set data_flatten but not data. Might evolve, it depends how we saw things.

- adapt shift (wok with data_flatten but should probably be extended latter)
- adapt noise reduction (work with data_flatten)
- remove the data reduction widget because should be highly modify since the numpy.ndarra.view in the experiement.data appear. Should be re-done

/close #8

- update also gradient orange widget.

- also add information about advancement.

- now series is given as a file pattern (give file xxx_0000.edf) and we can browse through this dataset
- rework the Dataset __data to return a fabio `FileSeries`
- postpone the DataReduction to be proceeded by the Dataset to avoid loading of all frames.
- limited to single frame edf file.

create a sub class _MappingBase to get the same interface between IntensityMapping and GradientRemoval.
This also allow to use the PlotMapping class for both.

Add also the list of operation on the save experiment widget.

Current noise reduction are:

- creation of a sphere or a cylinder
- threshod
- background substraction