New CVE-ID Fathead Plugin

Greetings! Here's all my work on a Fathead plugin for displaying the description of a given [CVE-ID](http://en.wikipedia.org/wiki/Common_Vulnerabilities_and_Exposures). I've followed the instructions in the README file and it feels pretty much complete.

Unfortunately, since duckpan doesn't work with Fathead plugins, I have no way of testing it except for manually viewing the output.txt file. It looks good to me though.

My only concern is that there's no place to specify when the plugin is actually triggered. There's nothing like a Spice `triggers()` function where you give the appropriate regex. Perhaps Fathead plugins are handled differently; I just didn't see anything in the tutorial.

Hopefully, I've done everything right. I'll be glad to fix anything that needs improvement.