Improved node management.

- List node by node types
- fixed the trash/restore/delete workflow
Added messaging module to send message to cms users (by email for now).
Added early protection for cache, export and import functionalities.

modules/node/persistence/cms_node_storage_null.e

@@ -59,6 +59,12 @@ feature -- Access: node
 			create {ARRAYED_LIST [CMS_NODE]} Result.make (0)
 		end
 
+	recent_nodes_of_type (a_node_type: CMS_CONTENT_TYPE; a_lower: INTEGER; a_count: INTEGER): LIST [CMS_NODE]
+			-- Recent `a_count` nodes of type `a_node_type` with an offset of `lower`.
+		do
+			create {ARRAYED_LIST [CMS_NODE]} Result.make (0)
+		end
+
 	recent_node_changes_before (a_lower: INTEGER; a_count: INTEGER; a_date: DATE_TIME): LIST [CMS_NODE]
 			-- List of recent changes, before `a_date', according to `params' settings.
 		do