Refactored and update CMS hooks design. (Move from CMS_RESPONSE to CMS_API).

Moved content_types and content_type_webform_managers from CMS_RESPONSE to CMS_API.
Updated the way to output content (node, ...) to html page.
   See CMS_CONTENT_TYPE_WEBFORM_MANAGER.append_cointent_as_html_to (...).
   Added notion of "teaser" (short version of the content), as opposed to full content.
One can use CMS_API.html_encoder ... when possible, same for `formats', ...
Added bridge from CMS_MODULE_API to CMS_API's encoders.
Added new CMS_TAXONOMY_HOOK used to retrieve list of content associated with a specific term.
Moved up to CMS_RESPONSE a few features which was available only in specific descendants.

Added /taxonomy/term/{termid} implementation.

modules/feed_aggregator/feed_aggregator_module.e

@@ -12,7 +12,7 @@ inherit
 			module_api as feed_aggregator_api
 		redefine
 			initialize,
-			register_hooks,
+			setup_hooks,
 			permissions,
 			feed_aggregator_api
 		end
@@ -181,13 +181,13 @@ feature -- Handle
 
 feature -- Hooks configuration
 
-	register_hooks (a_response: CMS_RESPONSE)
+	setup_hooks (a_hooks: CMS_HOOK_CORE_MANAGER)
 			-- Module hooks configuration.
 		do
-			a_response.hooks.subscribe_to_block_hook (Current)
-			a_response.hooks.subscribe_to_response_alter_hook (Current)
-			a_response.hooks.subscribe_to_menu_system_alter_hook (Current)
-			a_response.hooks.subscribe_to_cache_hook (Current)
+			a_hooks.subscribe_to_block_hook (Current)
+			a_hooks.subscribe_to_response_alter_hook (Current)
+			a_hooks.subscribe_to_menu_system_alter_hook (Current)
+			a_hooks.subscribe_to_cache_hook (Current)
 		end
 
 feature -- Hook