COMP: Update EMSegment: add VTKv8 support

Also remove CMake warnings and fix module category


More details below:

------------------------------------------------------------------------
r17134 | COMP: Fix warning removing explicit setting of CMake policy CMP0017.

Setting of CMP0017 to OLD is not needed.

This commit addresses the following warning reported when using CMake 3.9.0:

```
CMake Deprecation Warning at /home/jcfr/Projects/Slicer-2-build/EMSegment/CMakeLists.txt:12 (CMAKE_POLICY):
  The OLD behavior for policy CMP0017 will be removed from a future version
  of CMake.

  The cmake-policies(7) manual explains that the OLD behaviors of all
  policies are deprecated and that a policy should be set to OLD only under
  specific short-term circumstances.  Projects should be ported to the NEW
  behavior and not rely on setting a policy to OLD.

```

See Slicer/Slicer#765

------------------------------------------------------------------------
r17133 | lassoan | COMP: Setting CMP0020 to NEW to remove build warnings

------------------------------------------------------------------------
r17132 | lassoan | ENH: Fixed IslandRemoval module category

It was "Filter", while the correct category name is "Filtering"

------------------------------------------------------------------------
r17131 | msmolens | ENH: Call InitializeObjectBase() in New() methods

In VTK8 it's necessary for New() methods to call InitializeObjectBase() on the
new object for proper tracking with vtkDebugLeaks. The standard macros
(vtkStandardNewMacro, vtkObjectFactoryNewMacro) handle this. For those classes
that don't use the macros, add calls to InitializeObjectBase().

Continue to support earlier versions of VTK by wrapping calls to
InitializeObjectBase() in checks for the preprocessor define
VTK_HAS_INITIALIZE_OBJECT_BASE.

It's possible that many of these implementations could be simplified by using
the standard macros.

See also:
- Kitware/VTK@e5c793d
- http:https://public.kitware.com/pipermail/vtk-developers/2016-September/034332.html

git-svn-id: http:https://svn.slicer.org/Slicer4/trunk@26203 3bd1e089-480b-0410-8dfb-8563597acbee

SuperBuild.cmake

@@ -282,7 +282,7 @@ list_conditional_append(Slicer_BUILD_BRAINSTOOLS Slicer_REMOTE_DEPENDENCIES BRAI
 
 Slicer_Remote_Add(EMSegment
  SVN_REPOSITORY "http:https://svn.slicer.org/Slicer3/branches/Slicer4-EMSegment"
- SVN_REVISION -r "17130"
+ SVN_REVISION -r "17134"
  OPTION_NAME Slicer_BUILD_EMSegment
  OPTION_DEPENDS "Slicer_BUILD_BRAINSTOOLS;Slicer_BUILD_QTLOADABLEMODULES;Slicer_USE_PYTHONQT_WITH_TCL"
  LABELS REMOTE_MODULE