Bug 166383 [Viewers] Provide Tabing from Editor to Editor
bundles/org.eclipse.jface/src/org/eclipse/jface/viewers/ColumnViewer.java
* may also implement {@link IColorProvider} and/or {@link IFontProvider} to
	 * provide colors and/or fonts.
	 * </p>
	 * 
	 */
	public void setLabelProvider(IBaseLabelProvider labelProvider) {
		Assert.isTrue(labelProvider instanceof ITableLabelProvider
				|| labelProvider instanceof ILabelProvider
				|| labelProvider instanceof CellLabelProvider);
		updateColumnParts(labelProvider);
		
		super.setLabelProvider(labelProvider);
	}
	/**
	 * Clear the viewer parts for the columns
	 */
	private void updateColumnParts(IBaseLabelProvider labelProvider) {
		ViewerColumn column;
		int i = 0;
		while ((column = getViewerColumn(i++)) != null) {
			column.setLabelProvider(CellLabelProvider
					.createViewerLabelProvider(labelProvider), false);
		}
	}
	/**
	 * Cancels a currently active cell editor if one is active. All changes
     * already done in the cell editor are lost.
	 * 
	 * @since 3.1 (in subclasses, added in 3.3 to abstract class)
	 */