Added support for log stored in CMS_STORAGE.

Added support for custom value stored in CMS_STORAGE.
Added optional css classes addition to CMS_BLOCK output.
Refactored storage, to manage node from node module code only (or mostly).

TODO: improved view for a cms node, for now hardcoded.

examples/demo/modules/demo/cms_demo_module.e

@@ -88,7 +88,7 @@ feature -- Handler
 		local
 			sql: STRING
 		do
-			if attached {CMS_STORAGE_SQL} a_api.storage as sql_db then
+			if attached {CMS_STORAGE_SQL_I} a_api.storage as sql_db then
 				sql_db.sql_query ("select count(*) from tb_demo;", Void)
 				if sql_db.has_error then
 						-- Initialize db for demo module