Add the possiblity to assign human-friendly names for feature bins

[antoinecarme]

These names can then be used as real causes in external applications.

[antoinecarme]

A very good example can be seen on page 2 of this dcoument :

https://kdd11pmml.files.wordpress.com/2011/09/p2_flint_guazzelli_kdd_20112.pdf

[antoinecarme]