Resolve wording inconsistency

AND and OR filter docs talk about different targets for the operators. I
believe that both should be described in terms of modifying other 'filters'.
I also added articles for easier (human) parsing. This fixes #4762

Closes #7165
CORS: Allowed to configure allow-credentials header to work via SSL

This adds support to return the "Access-Control-Allow-Credentials" header
if needed, so CORS will work flawlessly with authenticated applications.

Closes #6380