+ change model->common_model->resource_name()
into surf_model_resource_by_name(model)
(less redirections, less function to write when defining a model)
+ * Unify the types of models in a uniq s_surf_model_t (using an union)
XBT:
* Add xbt_set_get_by_name_or_null() [Silas De Munck]