Update docstring for using pathtools.
Minor change in control flow, add documentation.
Move gen_stitching_macro_code() to imagej module.

And adjust it for using volpy.experiment.MosaicExperiment objects.

No testing done yet!
Add "supplement" dict to ImageData.
Add methods for tilenumbers, stage coordinates and dimensions.
MosaicDataCuboid: add get_overlap().
ImageDataOIF: implement parsing of Z/C/T dimensions.