Bug 174701 [Viewers] ViewerRow should be reused instead of connected to the Item
Currently we create a ViewerRow ver every Item we create this can degrade performance, we should cache the row and reuse it
bundles/org.eclipse.jface/src/org/eclipse/jface/viewers/ColumnViewerEditor.java
public static final int TABBING_VERTICAL = 1 << 3;
	/**
	 * Should tabing from column to column with in one row be supported
	 */
	public static final int TABBING_HORIZONTAL = 1 << 4;
	/**
	 * 
	 */
	public static final int KEYBOARD_ACTIVATION = 1 << 5;
	
	private int feature;
	/**
	 * @param viewer
	 * @param editorActivationStrategy
	 * @param feature
	 */
	protected ColumnViewerEditor(ColumnViewer viewer,
			ColumnViewerEditorActivationStrategy editorActivationStrategy, int feature) {
		this.viewer = viewer;
		this.editorActivationStrategy = editorActivationStrategy;
		if( (feature & KEYBOARD_ACTIVATION) == KEYBOARD_ACTIVATION ) {
			this.editorActivationStrategy.setEnableEditorActivationWithKeyboard(true);
		} 
		this.feature = feature;
		initCellEditorListener();
	}
	private void initCellEditorListener() {
		cellEditorListener = new ICellEditorListener() {
			public void editorValueChanged(boolean oldValidState,
					boolean newValidState) {