Improve description of apps

• from pr #528
• commits from: @lheagy
• review from: @sgkang

First impressions

• add the case history image to the index page
  

Apps

• more description on how to get up and running with Binder, Azure
  

General cleanup

• update copyright year to 2018
• bibtex cleanup
• add live links that are slow to resolve to the linkcheck ignore
• add versioning info to the site, including links to release notes for the changes with each version