Summary of bug description
   * actual behaviour
   QmitkStdMultiWidget creates render windows with same names (unnamedrenderwindow)   
   * expected behaviour
   QmitkStdMultiWidget creates render windows with specified names
   
Cause of the bug
A name was not set, so the default value is set to the rendow window

Proposed solution
Set name in the constructor of the render window instantiation in QmitkStdMultiWidget

Affected classes
QmitkStdMultiWidget

How will the bugfix get tested?
Add GetName() in the unit test of the QmitkStdMultiWidget or in the RenderWindow