RF fiducials_gui:  separate model from GUI
TEST fiducials_gui
WIP fiducials_gui:  enhance pick precision
RF coreg_gui:  separate model from GUI
ENH RawSource:  expose lpa, nasion and rpa
FIX:  lock fiducials
RM unnecessary wrappers
imports (paths -> coreg)
coreg_gui
STY
TEST coreg_gui