Remove segmentation slice info method from stack module
Remove segmentation slice info method from stack module

This method isn't needed in it's current form. Most parts of the related
code was removed recently. The segmentation code is currently reworked
in a separate branch.

fzadow/CATMAID,htem/CATMAID,fzadow/CATMAID,htem/CATMAID,fzadow/CATMAID,htem/CATMAID,fzadow/CATMAID,htem/CATMAID