Combine new post and RSS for better visual appearance. Do remove hard coded staff and let themes who use it override it with CSS

Redirect to absolute url of respective Web Section so if 'Renderer ID' is set (as usually when a web section is used for forum) the UI displays iforum UI which is not the case when default 'view' of Web Section is used if we redirect to using form_id.
As thread is show immediately correct message to not confuse users.

because the list of threads for Anonymous should be provided through predicate in Web Section, not from the module itself.

Forgotten be part of  9a710678

This might break RSS rendering

And Chameleon does not workaround by lowercasing them automatically.

Also fix a regression in erp5_web, which was introduced when naming convention
test was reapplied.

If no threads are found this means no posts exists and no need to create a SQL query with empty parents (which would return all posts regardless if the belong to web section or not).

Allow that not index (yet ) discussion posts to be show under a discussion thread view using passed from request new unindex discussion post url.

Split Discussion Thread reference generator into a separate testable method. Be more strict in generated reference.

Add fieldset class selector which can be used to override fault one when customizing forum's appearance.

Use permanent URL where possible.

Use nice URLs to access from RSS Discussion Post.

Improve default Discussion Thread Module view.

Revert 17045076 (we do not need to generate all entries per feed request only the most recent once as client code is expected to keep a "local" copy instead).