Renamed node_api and node_storage by blog_api and blog_storage in related CMS_BLOG_* classes. Mainly to avoid confusion with NODE_ classes.

Merged CMS_BLOG_CONFIG with CMS_BLOG_API.
In CMS_BLOG_API, prefer argument of type CMS_USER, rather than using directly user id.
Added a CMS_EDITOR_CONTENT_FORMAT for now, to be the format editable by the WYSIWYG editor.
Added CMS_MODULE.is_initialized: BOOLEAN to equip router, and module_api with expected preconditions.

Fixed typo, especially in log output.
Corrected a few routine names such as add_authors that should not be a function according to its name.
Converted various function returning html content, to procedure appending html content to an output string to minimize temporary string object creation.
Cosmetic: added spaces to make code easier to read, and indentation.

src/service/cms_api.e

@@ -185,8 +185,10 @@ feature -- Query: module
 	module_api (a_type: TYPE [CMS_MODULE]): detachable CMS_MODULE_API
 			-- Enabled module API associated with module typed `a_type'.
 		do
-			if attached module (a_type) as mod then
-				Result := mod.module_api
+			if attached {CMS_MODULE} module (a_type) as mod then
+				if mod.is_enabled then
+					Result := mod.module_api
+				end
 			end
 		end