Tb montage enh

Adds montage option to edf and brainvision modules to provide standard import of electrode points.
Adds fiducials to the montage.
Organization of transformation functions into the transformation module.
sorry, but could you explain the problem with the cal entry? I understand the propagation to epochs, and I understand that the value is stored in 32-bit and could lose precision, but i don't understand the problem if I move the scaling out of the cal entry