Fix for Bootstrap 3.1+

Thanks for your work on this!  This is a quick fix for Bootstrap 3.1+ where the matching z-index value of the .lightbox class and the included Bootstrap .modal-fade class caused the modal overlay to appear over the top of the lightbox.  I just tweaked the .lightbox class to be +1 z-index from the .modal-fade in BS 3.1.1.

Sorry about some of the spacing in my css files.  Feel free to kill my shameless credit in the .less file too - I actually thought I took that out.