Updating VTK
- Merge topic 'virtualize_selection_methods'
- Merge topic 'windows_keyword_issues'
- Merge topic 'fixEqualizerWidget'
- Merge topic 'vtkInstallCMakePackageHelpers-add-find-package-hints-for-openvr'
- Merge topic 'windows_compiler_issues'
Edited by Mathieu Westphal (Kitware)