COMP: Fix unused variable warnings in vtkSlicerCLIModuleLogic

git-svn-id: http://svn.slicer.org/Slicer4/trunk@22391 3bd1e089-480b-0410-8dfb-8563597acbee
COMP: Fix unused variable warnings in vtkMRMLMarkupsStorageNode

git-svn-id: http://svn.slicer.org/Slicer4/trunk@22392 3bd1e089-480b-0410-8dfb-8563597acbee
COMP: Fix "sign-compare" warning in vtkSlicerMarkupsLogic

vtkSlicerMarkupsLogic.cxx: In member function ‘void vtkSlicerMarkupsLogic::ConvertAnnotationFiducialsToMarkups()’:
vtkSlicerMarkupsLogic.cxx:882: warning: comparison between signed and unsigned integer expressions [-Wsign-compare]
vtkSlicerMarkupsLogic.cxx:954: warning: comparison between signed and unsigned integer expressions [-Wsign-compare]

git-svn-id: http://svn.slicer.org/Slicer4/trunk@22393 3bd1e089-480b-0410-8dfb-8563597acbee
BUG: Fix crash preventing the same color file to be loaded more than once

As the documentation associated "AddNode" method explains, in the case
of singleton node, the return node should be considered instead of the
one passed to the method.

AddNode documentation:

/// [...]
/// If node is a singleton, and a node of the same class with the
/// same singleton tag already exists in the scene, \a nodeToAdd is NOT
/// added but its properties are copied (c.f. vtkMRMLNode::CopyWithScene())
/// into the already existing singleton node. That node is then returned.

Fixes #2989

git-svn-id: http://svn.slicer.org/Slicer4/trunk@22394 3bd1e089-480b-0410-8dfb-8563597acbee