extractAll.sh doesn't work on macOS without changes

[thully]

When running the extractAll.sh script on macOS, I get the following error:

readlink: illegal option -- f
usage: readlink [-n] [file ...]
usage: dirname path

To resolve this, I had to install the GNU version of readlink (it's in the coreutils Homebrew package), and then change the script to reference greadlink. Perhaps this can be referenced in the readme or worked around in some way.

[jhugestar]

Thanks. I have removed the dependency.