Contact page, template title tag, PostgreSQL connection
 - Added a fourth static page, /static_pages/contact,
   routes and controller action
 - Configured the development and test environments to
   connect to a local PostgreSQL database, which had a
   painful learning curve but will be much easier in the future.
 - Modified the title tag in the application layout to use a
   helper method full_title, which omits the pipe "|" if a page
   title is not provided.