Updated the wedding app and some custom tags

* Added a gallery page to the wedding app. Needs work: pagination,
  thumbnailizing, and testing with images
* Added the gallery to wedding/urls.py and made the gallery view
* Added a img_link tab - not good this is a hack. Needed for testing. Can
  stay.
* Updated gallery.css to add cell padding to <li>

Still have not merged the wedding branch into master.