! get_preferred_language() didn't account for malformed Accept-Language headers. (Subs.php)
* Attempting to overhaul the .note class system. Everything is now subdued: .notevoid is removed, .note will do a similar job; while .note will be replaced by .notewarn (orange hue), and the original .notewarn disappears (too visible for my current taste). The .notenice class remains, but gets a more pastel tone. (Boards.template.php, MessageIndex.template.php, index.template.php, index.css, sections.css)

@ Note: I'm reserving the right to revert this commit entirely. It's ONLY there to test the pastel effect and determine whether it's worth it.