Added CMS_NODE_TYPE as descendant of CMS_CONTENT_TYPE,
in case we have content which is not a node in the future.
(probably useless, but for now, this extra abstraction is harmful)
Moved all node related code under node module cluster.
Applied comments from Javier Velilla.
Code cleaning.
but this is an example about on to add a new content type, and support it.
Fixed new node form workflow.
The current state is not final, it requires many changes, but for now, it implements a node editing workflow.
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.
Protected cms service from registering many time the same module type.
Moved library/persistence/implementation/* under library/persistence/.
Moved site/www/themes to site/themes
For SQLite storage driver, auto create sqlite db file using associated sql script (to be completed).
Added code in demo module to reuse storage for module purpose.
Always call sql_post_execution in sql_query and sql_change, and not anymore by the callers.
Removed is_web and is_html from {CMS_SETUP}, it was not used.
Reused SHARED_*_ENCODER in CMS_ENCODERS
Added CMS_API.logger rather than using directly the SHARED_LOGGER.log ...
Centralize the implementation of current_user in CMS_REQUEST_UTIL
Removed the inheritance on WSF_FILTER for node handlers, since it is useless and unused.
Added CMS_NODE_API and CMS_USER_API
Prefix html id for block generated html items with "block-", to avoid css name conflict on "main", "content" or similar.
Code cleaning
