Non ASCII characters

[Jean-Baptiste-Camps]

* checking R files for non-ASCII characters ... WARNING
Found the following files with non-ASCII characters:
  PCC.Stemma.R
  PCC.overconflicting.R
Portable packages must use only ASCII characters in their R code,
except perhaps in comments.

Ça a l'air d'être dans les commentaires en effet, mais à vérifier.