feature/slice-draft

This pull request introduces the model classes for the Slicing.

* Range
** consists of lower and upper bound.

* SliceCube
** Array of ranges. The number of ranges defined the dimensions of the cube, and the ranges of each dimension define the size of the cube.

* Slice
** Array of SliceUnits. The order is important!!
** data -> array of n-dimensions representing the slice itself.


This pull request does not implement all this methods. It implements the put and contains.