Watch those param orderings!

Listening To : Shooby Taylor, the human horn.

Refract and Faceforward have I and N paramaters specified in different orders! How many times has that caught me out ?!?!?

     vector refract( vector I, N; float eta )
     vector faceforward( vector N, I )

Also clamp and mix/smoothstep have different orderings.

     type clamp( type a, min, max )
vs
     type mix( type x, y; float alpha )
     type smoothstep( type min, max, value )