Rewrite symlink handling in the merge script
Rewrite symlink handling in the merge script

readlink -e (or -f / -m) isn't supported on Mac OS X, so I shouldn't be using it. Add some documentation on how this script works.
ThierryGoubier/GitFileTree-MergeDriver,ThierryGoubier/GitFileTree-MergeDriver,DamienCassou/GitFileTree-MergeDriver