Updated CMS node and blog to remove extension data.

Comments: minor update.

Updated CMS_NODE_STORAGE_I API.
Delete a node using a node as formal parameter instead of node id.
Clean code and update log information.

Added precondition to delete node to accept nodes with a valid a id.

Added missing assertions tag names.

modules/node/persistence/cms_node_storage_null.e

@@ -106,7 +106,7 @@ feature -- Node
 		do
 		end
 
-	delete_node_by_id (a_id: INTEGER_64)
+	delete_node_base (a_node: CMS_NODE)
 			-- <Precursor>
 		do
 		end