Create goostats
Make goostats accept file names as input instead
Create goodiff

Originally written by @BernhardKonrad at https://github.com/wltrimbl/2013-12-03-sesync/blob/9c7871ac909e853d19e901b430f626cbd4b3ee3a/lessons/shell-advanced/loops/goodiff
Append "bash" in front of "goostats" calls
Merge pull request #254 from rhiever/master

Fix references to "goostats" in beginner shell looping material