Add teardown events support to Eventable
Add teardown handling for App
Add teardown handling for InteractionMachine
Tear down InteractionMachine when as part of the steps taken when terminating the sandbox
Merge branch 'feature/issue-196-apptester-doesnt-tear-down-its-app-properly' into develop
Merge branch 'develop' into feature/issue-196-add-state-type-that-divides-up-content-into-pages
Fix up PaginatedState's default page function (hopefully properly this time)