changed modify_objet method to update_objet for better clarity
maj in update_objet processing, adding the date
setting basics of Ressource_text class
get_objet_list method updated
updated save() method of Ressource_text class
added callback check function in adding ressource texte process
form validation date one ajout_relation
creation of ressource_graphique and its _model
unfinished work on ajout image
ajout_ressource_graphique completed
Merge branch 'paulyves' into development