ENH: allow CFoods to provide update_flags

src/caosadvancedtools/cfood.py

@@ -170,6 +170,7 @@ class AbstractCFood(object, metaclass=ABCMeta):
         self.identifiables = db.Container()
         self.item = item
         self.attached_items = []
+        self.update_flags = {}
 
     @abstractmethod
     def create_identifiables(self):

src/caosadvancedtools/crawler.py

@@ -549,7 +549,8 @@ carefully and if the changes are ok, click on the following link:
                 logger.info(
                     "Updating {} Records...".format(
                         len(cfood.to_be_updated)))
-            guard.safe_update(cfood.to_be_updated, unique=False)
+            guard.safe_update(cfood.to_be_updated, unique=False,
+                              flags=cfood.update_flags)
         except FileNotFoundError as e:
             logger.info("Cannot access {}. However, it might be needed for"
                         " the correct execution".format(e.filename))