modify database scheme
add ressource manuelle tables
add ressources numeriques models
add ressources methods in (etab)
change default avatar directory
fix default avatar path for apps
add an avatar neutre
add ressource numerique api
add create/remove ressource api
fix personnels bug
add ressources numerique method to etablissement model
return all ressources in (etab)
ajouter/supprimer des ressources numerique à l'etablissement
add date by default when creating a new resource numerique
link a ressource numerique to a service(ressource)
when creating a new ressource numerique
Merge branch 'ressources_manuel'

Conflicts:
	api/init.rb
delete related records in etablissement has ressource  when
deleting a resource
activate authentication on ressources api
add ressource_numerique method to user
add  ressource numerique api
a revoir