Create a Mac OSX version of exaslct

[tomuben]

Background

exaslct is not compatible with MacOsX due to two reasons:

1. Command readlink contains only a subset of the features of the linux version. We need to use greadlink (which comes with gtools, can be installed with "brew install coreutils")
2. Bash version is very old (3.6.2), we need at least 4.2 (due to usage of associative arrays)

Solution

We have two options here:

1. Write a slim version of exaslct which is specifically for MacOsX, which does not support the mount point handling. And which uses greadlink instead of readlink
2. Write exaslct in Go