Jenkins jclouds

@zach-shoylev can you review and offer some tips?

The Jenkin's jclouds-plugin has some usability issues, so I think a visual guide with some tips and warnings.  However, I'm not sure that just throwing all the images on a page like this is the best choice.  Other options may include adding more text to go along with the images, embedding a presentation/slideshow, or even doing a screencast.

So... if you can, please take a look and see if the guide works for you, then offer suggestions on presentation layout.

P.s.: I added a very simple "zoomable_img" tag, which creates an image with a link to itself.  This acts as a "zoom", because the image on the webpage is scaled down to fit the page layout.  The tag doesn't support separate full/thumbnail images or lightbox behavior.  I thought about adding that, but I don't want to add a lot of extra ruby/javascript/css unless it's a feature others would use and maintain.