This tasks integrates the latest developments, presented in T25622.
It will include the latest changes and bugfixes before it will be merged into master as a first open test version.
[x] solve initialization bugs
 fix blueberry crash
 perform tests
 build on Linux
 merge into master
 hide from outcry
= Important changes:
- context menu actions removed from the data manager view
- data manager now uses the `QmitkDataNodeContextMenu` from 'org.mitk.gui.qt.application'
- moved `OpenRenderWindowPart` from the data manager to the workbenchutil:
- moved implementation of `GetRenderWindowPart` (with `IRenderWindowPartStrategy`) from the abstract view to the workbenchutil
- possible migration conflict: views that rely on the `QmitkAbstractView` to provide `IRenderWindowPartStrategy` values now need to access the workbenchutil
- => e.g. inside the `QmitkSegmentationView`: `GetRenderWindowPart(OPEN)` becomes `GetRenderWindowPart(mitk::WorkbenchUtil::OPEN)`
- moved `QmitkInfoDialog` from the data manager plugin to 'org.mitk.gui.qt.application'
- moved `mitkIContextMenuAction` from the data manager plugin to 'org.mitk.gui.qt.application'