Floating point error amplification when target and eye are far from the origin

[bonsairobo]

There is an observable error in the camera angles for the first-person controller (at least), which seems to worsen as you get further from the origin. I assume this is introduced when creating LookAngles or maybe Quat. Anyway, I think it means that we'll need to store the angles separately rather than calculating them from global coordinates every frame.

This convinces me even more that we want separate coordinates systems for angles and positions, and a different type of smoother for each coordinate system.