Added support for multiple crouton managers
clean up of clearForActivities
MAtches formatting to rest of Crouton and improves some comments
Merge branch 'develop' into feature/multi_croutons
more documentation
formatting, comments and possibility to remove a Manager
adds missing break
Merge branch 'develop' into feature/multi_croutons
Merge branch 'develop' into feature/multi_croutons
Merge branch 'develop' into feature/multi_croutons
fixes copyright for LifecycleCallback