/**************************************************
  Coppermine 1.5.x Plugin - thumbnail_pdf
  *************************************************
  Copyright (c) 2010 S.J.Hoeksma
  *************************************************
  This program is free software; you can redistribute it and/or modify
  it under the terms of the GNU General Public License as published by
  the Free Software Foundation; either version 3 of the License, or
  (at your option) any later version.
  ********************************************
  
This plugin requires ImageMagick (convert) and ghostscript and  pre-installed and working on your server. 
It will create a thumbnail and normal image of the first page of your PDF file you upload.
Code is based on the video2flash_ffmpeg pulgin and the following web page
http://www.redvodkajelly.com/blog/2008/04/15/how-to-create-pdf-preview-images-in-php-part-2/
