added gzipped directory of scripts to enable homebrew recipe

The makefile is used to create a tarred & gzipped file containing each of the scripts that are then installed by Homebrew. I left a number of the tools out as I didn't think they fit with in Homebrew (e.g. the tools that had Weka as a dependency, as Homebrew doesn't install Weka). 

If you merge this pull request, I'll submit another PR to homebrew containing the recipe; I call it "dstutils." 

If you disagree with the scripts I've chosen to include, please let me know, I'm more than willing to change that.