Add extra presentation options for images

[hugopeek]

• [x] Image gallery with grid options
• [x] Images with slick slider enlargement
• [ ] Masonry grid for Overviews and Galleries

For slider with lightbox, see: http://mreq.github.io/slick-lightbox/demo/

[hugopeek]

Gallery and slider options are there. Will move masonry grid to a separate feature request.