Redesigned hooks system (moving from CMS_RESPONSE to CMS_API).

Indeed, hooks does not require RESPONSE interface,
   and should be setup before, at the system level (i.e CMS_API)
Added exportation solution via CMS_HOOK_EXPORT.
Updated blocks settings for demo example project.

modules/node/export/cms_export_node_utilities.e

@@ -0,0 +1,55 @@
+note
+	description: "[
+				Routines usefull during node exportation (see {CMS_HOOK_EXPORT}).
+			]"
+	date: "$Date$"
+	revision: "$Revision$"
+
+class
+	CMS_EXPORT_NODE_UTILITIES
+	
+inherit
+	CMS_EXPORT_JSON_UTILITIES
+	
+feature -- Access
+	
+	node_to_json (n: CMS_NODE): JSON_OBJECT
+		local
+			jo,j_author: JSON_OBJECT
+		do
+			create Result.make_empty
+			Result.put_string (n.content_type, "type")
+			Result.put_integer (n.id, "nid")
+			Result.put_integer (n.revision, "revision")
+			Result.put_string (n.title, "title")
+			put_date_into_json (n.creation_date, "creation_date", Result)
+			put_date_into_json (n.modification_date, "modification_date", Result)
+			put_date_into_json (n.publication_date, "publication_date", Result)
+			Result.put_integer (n.status, "status")
+			if attached n.author as u then
+				create j_author.make
+				j_author.put_integer (u.id, "uid")
+				j_author.put_string (u.name, "name")
+				Result.put (j_author, "author")
+			end
+			create jo.make_empty
+			if attached n.format as l_format then
+				jo.put_string (l_format, "format")
+			end
+			if attached n.summary as s then
+				jo.put_string (s, "summary")
+			end
+			if attached n.content as s then
+				jo.put_string (s, "content")
+			end
+			Result.put (jo, "data")
+			if attached n.link as lnk then
+				create jo.make_empty
+				jo.put_string (lnk.title, "title")
+				jo.put_string (lnk.location, "location")
+				jo.put_integer (lnk.weight, "weight")
+				Result.put (jo, "link")
+			end
+		end
+
+end