-RM-274-MR-WCustomWidget needs some more abstraction.
Currently we use WCustomWidget in histogramView and eegView modules. Both modules using it for renderning 2D content. However, both modules often have some long function-call-chains like @widget->getViewer()->getCamera()->getViewport()->width()@ as well as custom EventHandler classes. This means whenever a new module needs a custom widget it has to implement a lot of boilerplate code around the WCustomWidget with much OSG internals. I propose a WCondition inside WCustomWidget which may notify the modulestate, as well as a GUI event.
(from redmine: created on 2013-04-04, closed on 2013-11-12)