Updated version of Jochen Lenz' relativepath.m for finding the relative path of a directory or filename relative to another (absolute) path.
The following improvements have been made over the original submission:
* More system agnostic – uses case-sensitive filenames when running under Linux/OSX
* Now supports input filenames as well as paths
Inspired by: relativepath.m
Create scripts with code, output, and formatted text in a single executable document.