OZP-10: handle dashboard deletes

- activate first dashboard when one is deleted
- prevent random dashboard switches caused by switcher not preventing
default
- add tests
Merge feature/ozp-10-dashboard into master
OZP-10: synchronously save dashboard on window beforeunload event
Merge branch 'master' of https://github.com/ozoneplatform/ozp-owf
Merge feature ozp/ozp-10-dashboard into master