Update screenshots in "Introduction to Phabricator" slides at https://commons.wikimedia.org/wiki/File:Introduction-to-Phabricator-WikiCon-2016.pdf because I'd like to use next month for sessions at Wikimania:
- Workboards have new icons in the column headers. Pages: 7,21,22,23
- Star dropdown button is now a Bookmark dropdown button, see T160125#5305738. Pages: 11,12,13,14,26,27