Adding sorting capabilities to rasdaman

[Piero Campalani]

It would be a benefit in the potential of WCPS/rasql queries to add functions for sorting an array, for instance for computing rank correlations and normal probability plots.

As a first step, enabling 1D marrays to be sorted.

Useful links:

• ​http://docs.scipy.org/doc/numpy/reference/arrays.ndarray.html

  ndarray.sort([axis, kind, order])	Sort an array, in-place.
  ndarray.argsort([axis, kind, order])	Returns the indices that would sort this array.