Provide more structure for citations in publications table

[jsstevenson]

Right now, the citation column is created with this code

    def citation
      if !result.nil? && result.key?('authors')
        [first_author, year, article_title, journal].compact.join(', ')
      else
        ""
      end
    end

A user could re-create original structure by splitting up this string by columns. However, there's no reason why we can't just keep these as separate columns, retain more author and publication information, maybe get a DOI... lots of options.