Use nullptr instead of 0 and NULL.

Applications/DataExplorer/Base/CheckboxDelegate.h

Applications/DataExplorer/Base/ColorPickerPushButton.cpp

Applications/DataExplorer/Base/ColorPickerPushButton.h

...ications/DataExplorer/Base/QNonScalableGraphicsTextItem.h

Applications/DataExplorer/Base/QValueTooltipSlider.h

Applications/DataExplorer/Base/StrictIntValidator.h

Applications/DataExplorer/Base/TreeItem.cpp

Applications/DataExplorer/Base/TreeModel.cpp

Applications/DataExplorer/Base/TreeModel.h

Applications/DataExplorer/Base/TreeModelIterator.cpp

Applications/DataExplorer/Base/TreeModelIterator.h

Applications/DataExplorer/DataView/BaseItem.h

Applications/DataExplorer/DataView/ColorTableModel.h

Applications/DataExplorer/DataView/ColorTableView.h

Applications/DataExplorer/DataView/CondFromRasterDialog.cpp

Applications/DataExplorer/DataView/CondFromRasterDialog.h

...ations/DataExplorer/DataView/CreateStructuredGridDialog.h

...ations/DataExplorer/DataView/DataExplorerSettingsDialog.h

...ications/DataExplorer/DataView/DiagramView/DetailWindow.h

...cations/DataExplorer/DataView/DiagramView/DiagramList.cpp