Isppa and heating maps are incorrectly transformed to MNI space

[KTZ228]

Caused by smooth_and_crop_layered & smooth_and_crop_skull functions not applying transforms to MNI transformation matrix but only to the structural data itself.
Since you would only transform subject data MNI space when looking at groups, it will not affect the individual results.

[KTZ228]

When comparing *final_medium_masks_orig* to *final_medium_masks_MNI* we can see that incorrect labels such as neural tissue are placed alongside the borders of bodies in the latter whereas these were not yet there in the former. Indicating that this issue is caused by the translation of the segmented mask to MNI space.

[KTZ228]

This is fixed, will submit in a future pull request, additional comments explaining the issue and fix can be found here:
simnibs/simnibs#175