Rewrote bounding box algotithm. Fixes issues 5967, 6154, 6196, 6211. Instead of being vertex-based, it is now primitive (point, line or dissected triangle) based, with proper clipping. Also, screen position is now calculated based on viewport values, instead of "guesstimating". This fixes many graphical glitches in Paper Mario: TTYD and Super Paper Mario. Also, the new code allows Mickey's Magical Mirror and Disney's Hide & Sneak to work (mostly) bug-free. I changed their inis to use bbox. These changes have a slight cost in performance when bbox is being used (rare), mostly due to the new clipping algorithm. Please check for any regressions or crashes.