Pre-release of software-agnostic quantile implementation

This is a pre-release of the quantile software for software-agnostic implementations (R/SAS/Python/C) of common quantile estimation algorithms.

This source code is released as a proof of concept for Grazzini and Lamarche's article:

Grazzini J. and Lamarche P. (2017): Production of social statistics... goes social!, in Proc. New Techniques and Technologies for Statistics.

and aims at promoting software/language-agnostic development and deployment of statistical processes.