Have shell script follow symlink

[saneki]

This is so a symlink to the script can be placed in a directory such as /usr/bin and function correctly.

Assuming that this doesn't break anything on OS X.

[darealshinji]

Line ending of the shell script should also be changed to Unix or otherwise you get this warning: bash: ./disunity.sh: /bin/sh^M: bad interpreter: No such file or directory