Delete .htaccess file

Not needed, I use jekyll redirects plugin.
Convert publications to separate post-like files

Each publication is a separate markdown file in the /pubs/_posts directory.
These are treated as special posts with category='pub' and displayed in
different groups and in different orders on the pubs-by-year and pubs-by-tag
pages

The main /research/publications page now simply has two links, one to pubs by
year and one to pubs by tag/topic
Re-organized tags in publications

Changed and condensed some tags in publication markdown file yaml metadata.
Cleaned up links in prospectives page