[Olena] Re: oln 10.61: attributes opening/closing

Index: olena/ChangeLog from Giovanni Palma <giovanni@lrde.epita.fr>

* oln/morpho/attributes.hh: Add file. Add new atributes. * oln/morpho/attribute_union_find.hh: Correct genericity errors. * oln/morpho/attribute_closing_opening.hh: Add some prototypes for attribute opening/closing.

* oln/utils/histogram.hh: Add comments.

Il manque un paragraphe dans NEWS je suppose.