Add caption link capability

Was doing a portfolio website and needed the ability to link to external websites from the lightbox view.

    <a href="images/image-1.jpg" rel="lightbox" title="my caption">image #1</a>

shows the regular lightbox caption.

    <a href="images/image-1.jpg" rel="lightbox" title="my caption" data-webpage="www.google.com">image #1</a>

Will show a url link under the title of the Image in the lightbox view window

    <a href="images/image-1.jpg" rel="lightbox" title="my caption" data-webpage="www.google.com" data-webpage-title="Go To Google">image #1</a>

Will mask the link with the desired text.