1133 fix assistant call history

Closes #1133, is based on !83 (merged) - must be merged afterwards

Caused by breaking change in new uirouter - see:

• https://ui-router.github.io/docs/latest/modules/ng1_state_events.html
• https://github.com/angular-ui/ui-router/issues/2720
• https://ui-router.github.io/guide/ng1/migrate-to-1_0