COMP: Slicer welcome: Fix location of qrc files in UI file.

From: Jean-Christophe Fillion-Robin <jchris.fillionr@kitware.com>

git-svn-id: http://svn.slicer.org/Slicer4/trunk@23673 3bd1e089-480b-0410-8dfb-8563597acbee
STYLE: Display a warning message if no writers is found when using saveNodes

From: Jean-Christophe Fillion-Robin <jchris.fillionr@kitware.com>

git-svn-id: http://svn.slicer.org/Slicer4/trunk@23674 3bd1e089-480b-0410-8dfb-8563597acbee
ENH: Fixed color scalar bar by using vtkPVScalarBarActor

* Color scalar bar was enhanced and the bugs were fixed by adding Paraview vtkPVScalarBarActor to module's logic
* Replaced vtkScalarBarActor with vtkPVScalarBarActor
* Made the logic sensitive to dicom volume. (for none dicom volumes the
 color scalar bar would occupy 100% of the view's width)
* Change the format of foreground volume and label opacities to percentage
(e.g. from 0.4 to 40%)

From: Alireza Mehrtash <mehrtash@bwh.harvard.edu>

git-svn-id: http://svn.slicer.org/Slicer4/trunk@23675 3bd1e089-480b-0410-8dfb-8563597acbee