Pipeline: Source analysis: Co-registering MRI-M/EEG

[sarathykousik]

I would like to have some advice on co-reg procedures. In my experience MNE-ICP seems to work well, probably better than MNE-Py-Coreg(@MadsJensen: has this been fixed??). And both are great when working within the MNE-world. Is there a way one can smartly move the coreg to another toolbox like Fieldtrip? FT's coreg isn't great anyway.

[cjayb]

Relates to #11

[sarangnemo]

For simple fiducial-based or fiducial+headshape-based coregistration, my group still uses Nutmeg and imports the result into FieldTrip. Probably we'd have to add support for the Elekta headshape file format, but it's otherwise easy to implement. If there's another method that seems to work well from MNE, I'd be happy to reimplement it as FieldTrip-compatible Matlab code.