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: 

https://gist.github.com/llou/7335064#file-gistfile1-py

P.D. Sorry is my first pull request to any project, I am not sure if I have done it right. Don't be severe.