Convert rotation attribute to use degrees instead of radians

[bnolan]

Radians are great because they're natively supported in three, and I don't even know how we'll manage to do degrees with the euler angles with degrees, but it's really painful typing "0 0 0.707" when you mean '0 0 45". So I recommend we move to degrees (super noob mode).

Maybe, we could have something like css:

rotation="0 0 45deg"
rotation="0 0 0.707rad"
rotation="0 1 0 0.707"

The last one would be quaternion style, with an axis vector and rotation in radians. That one would actually be quite handy for doing rotations that are tricky to type by hand because of the way euler angles are converted (X then Y then Z) to quaternions.

Thoughts?