allow import of txt and add todo on database

pymath/stat/dataset.py

@@ -7,6 +7,8 @@
 #
 #
 
+# TODO: Rendre toutes les réponses Explicable!! |mar. janv. 12 09:41:00 EAT 2016
+
 from math import sqrt, ceil
 from .number_tools import number_factory
 from .random_generator import random_generator