C13 Cloudant support, Common event management

Chapter 13 has had a problem when cloud foundry restarts. When this happens, the previous data management approach in Chapter 13 resulted in all of the cards being lost. This release introduces Cloudant as a persistence service for cards so that when CF restarts, all cards are automatically recreated. This only recreates the cards created when the autoload process is run. Cards created via the admin console are not preserved. Implementing this additional logic is left to the student.

Event management for chapters 1-12 was sort of brute force and did not work with Chapter 13. There were also issues which appeared when multiple browser pages were opened simultaneously against the local nodejs server which resulted in events being lost. These issues have been resolved by implementing the logic and technology used in Chapter 13 for all earlier chapters.