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
} else {
				rv = searchPreviousCell(row, viewer, columnIndex - 1,
						startIndex);
			}
		} else {
			if ((feature & TABBING_CYCLE_IN_ROW) == TABBING_CYCLE_IN_ROW) {
				
				if (columnIndex - 1 != startIndex) {
					
					
					
					rv = searchPreviousCell(row, viewer, row.getColumnCount(),
							startIndex);
				}
			} else if ((feature & TABBING_MOVE_TO_ROW_NEIGHBOR) == TABBING_MOVE_TO_ROW_NEIGHBOR) {
				ViewerRow rowAbove = row.getNeighbor(ViewerRow.ABOVE, false);
				if (rowAbove != null) {
					rv = searchPreviousCell(rowAbove, viewer, rowAbove
							.getColumnCount(), startIndex);
				}
			}
		}
		return rv;
	}
	private ViewerCell searchNextCell(ViewerRow row, ColumnViewer viewer,
			int columnIndex, int startIndex) {
		ViewerCell rv = null;
		if (columnIndex + 1 < row.getColumnCount()) {
			ViewerColumn column = viewer.getViewerColumn(columnIndex + 1);
			if (column != null && column.getEditingSupport() != null