Updated node extension implementation.
Updated known permissions for node module.
Improved code for node storage extension , in preparation to code factorization.
Ensured that author is updated when saved.
Now, all formats used by CMS are instances of CMS_FORMAT, mainly to prepare the admin section in order to define format by config/database.
CMS_NODE_API provides all queries to access the content types, and formats, this way a module can easily alter the formats by adding a new filter.
TODO: see how to integrate permission checking, to control who can use a specific format (such as full HTML).
Added CMS_HOOK_RESPONSE_ALTER to give a last chance to alter the response before rendering.
This hook should not be used, when there are other alternative hook that answer the need, but this is proposed for now, as a way to alter response by adding css, js url, ...
Moved blog under official modules folder.
Cleaned theme of demo example project.
Renamed NODE_MODULE as CMS_NODE_MODULE.
