Added shorthand regular expression test to filter stdout from command ex...

I was having trouble trying to run commands on a dd-wrt router as the motd included a lot of "=":

==========================================================
 
 ____  ___    __        ______ _____         ____  _  _ 
 | _ \| _ \   \ \      / /  _ \_   _| __   _|___ \| || | 
 || | || ||____\ \ /\ / /| |_) || |   \ \ / / __) | || |_ 
 ||_| ||_||_____\ V  V / |  _ < | |    \ V / / __/|__   _| 
 |___/|___/      \_/\_/  |_| \_\|_|     \_/ |_____|  |_| 
 
                       DD-WRT v24-sp2
                   http://www.dd-wrt.com
 
==========================================================

 so I implemented a regex filter to test shorthand key value expressions.

I have build a script for testing the expresion and is in gist: