#108: Safe check before get a scenario to avoid exception.

See : https://groups.google.com/d/msg/pivot4j-list/UudP1RSrdRU/by84nMGW-WQJ
Add missing onViewChange() call.
Fix #117: Support for bookmarkable URL for reports.

http://github.com/mysticfall/pivot4j/issues/issue/117
Merge branch 'master' of https://github.com/mysticfall/pivot4j
Merge branch 'master' of github.com:voyaging/pivot4j