- add [ad_conn behind_proxy_p] and [ad_conn behind_secure_proxy_p] to centralize logic - use the new function fix [security::get_qualified_url] when running behind a proxy
- Introduce new proc ad_sanitize_filename implementing current best practices for ensuring a valid filename on most filesystems. - Use it in every place where filename sanitization is performed in the code and deprecate fs::remove_special_file_system_characters.
TODO deprecate also util_text_to_html? Use case of sanitizing urls and filenames might have different requirements.