Updated Flickr Plugin

Made a few changes to the Flickr plugins to improve the display of Mailchimp email campaigns
Changed the gallery/album wrapper to a div with spans per image instead of using a list
Changed the 'summary' selection from 6 images to 8 images to improve how it looks on the home
page (not really for the gallery site, but the changes have been deployed across all sites)
Amended the feed_content.html file to include the correct content (galleries were only
displayed on posts with a layout type of 'gallery', but on the gallery site the layout type used
in 'album'