CodingStyle: fix the way we get interfaces from components

We were not considering interface without the I prefix for component
interfaces

product/ERP5Type/CodingStyle.py

@@ -65,10 +65,11 @@ def getSkinPrefixList(self):
   skin_prefix_list.extend(self.portal_types.getMixinTypeList())
 
   # Add interfaces prefix
-  skin_prefix_list.extend(self.portal_types.getInterfaceTypeList())
-  # XXX getInterfaceTypeList seems empty ... keep this low-level way for now.
+  # XXX getInterfaceTypeList does not include file system interfaces ... keep this low-level way for now.
   from Products.ERP5Type import interfaces
-  for interface_name in interfaces.__dict__.keys():
+  for interface_name in (
+      list(interfaces.__dict__.keys())
+      + list(self.portal_types.getInterfaceTypeList())):
     if interface_name.startswith('I'):
       skin_prefix_list.append(interface_name[1:])
     # XXX do we really add with the I prefix ?