Glitchy hiboxes for HPath quadratic curves

[snarks]

HPath's hitbox glitches when using quadratic curves with control points at certain heights. As always, I think this is probably due to my methods' lack of precision tolerance.

Possible workarounds:

• Limit the precision when calling adjust() or endPath() to prevent non-round values from cropping up with the vertices.

I mark this as a low priority bug, because:

• the glitch that's there isn't as bad, because it's limited by super.containsRel()
• the more common cubic bezier vertices are working mostly fine AFAIK
• I can only reproduce this at very specific conditions

So yeah, I'll suspend this one so I could move on with other stuff.