Avoid exceptions to check view functionality
We currently use exceptions to check if the dependencies of a view are available and disable the view then. As a result it is complicated to distinguish between bugs in the view and correct behavior if a dependency is not available. The views should check if they are working, and then register themselves in some manager / factory. Only this factory should then be used to create the views. This would also make the implementation of user views (#659) quite easy.
(from redmine: issue id 962, created on 2012-04-26 by Tobias.Winchen)