updated with new features

--  Changed wkhtmltoimage-i386 to wkhtmltoimage to reflect the new name in new version
--  Added ability to take script args to adjust format type and quality level.
--  Added default behavior to create an index.html preview file or specify name
--  Added additional checks for open ports before running
--  Added verbose status output
--  script-args:
--    http-screenshot.format = jpg, png, etc (default is jpg)
--    http-screenshot.quality = 0-99 (default is 75)
--    http-screenshot.indexpage = file.html (default is index.html)