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
&& column.getEditingSupport().canEdit(
							row.getItem().getData())) {
				rv = row.getCell(columnIndex + 1);
			} else {
				rv = searchNextCell(row, viewer, columnIndex + 1, startIndex);
			}
		} else {
			if ((feature & TABBING_CYCLE_IN_ROW) == TABBING_CYCLE_IN_ROW) {
				
				if (columnIndex + 1 != startIndex) {
					
					
					rv = searchNextCell(row, viewer, -1, startIndex);
				}
			} else if ((feature & TABBING_MOVE_TO_ROW_NEIGHBOR) == TABBING_MOVE_TO_ROW_NEIGHBOR) {
				ViewerRow rowBelow = row.getNeighbor(ViewerRow.BELOW, false);
				if (rowBelow != null) {
					rv = searchNextCell(rowBelow, viewer, -1, startIndex);
				}
			}
		}
		return rv;
	}
	/**
	 * Position the editor inside the control
	 * 
	 * @param w
	 *            the editor control
	 * @param item
	 *            the item (row) in which the editor is drawn in