+ *
+ * FIXME: We need something to record undo in partial grids for mathed.
+ * Right now we use recordUndoInset if more than one cell is changed,
+ * but that puts the cursor in front of the inset after undo. We would need
+ * something like
+ * recordUndoGrid(LCursor & cur, Undo::undo_kind kind, idx_type from, idx_type to);
+ * and store the cell information in class Undo.