An "Unbind" option for key-binds and controls.

If anyone can correct me on this, I would be VERY grateful. But to my understanding there isn't any unbind method for setting buttons to be 'nothing'. Other than setting something else as that same button, in which it cancels out the other to unbind it, which.. should be better that.
I'm not sure all the situations this becomes appropriate, but it really should've been an option regardless.