Improve raw data checker example.
Improve raw data checker example.

Made into executable script that takes either a file
or a directory as command line argument. For more information,
use the help:

$ examples/data_checks.py --help

Change-Id: I901cd6b6eaa50001508be998e46b21952056c21e

lidakanari/NeuroM,eleftherioszisis/NeuroM,mgeplf/NeuroM,BlueBrain/NeuroM,juanchopanza/NeuroM,liesbethvanherpe/NeuroM,wizmer/NeuroM