#65 Olifant v3: Row count display not updated after row deletion

[Yves Savourel]

The row count indicator in the status bar is not updated after one or more rows are deleted by the user.

This is because CommitChanges() is not called to allow the undo. Also, we do not want to call it after each row deletion when deleting many rows, but no event seem to be triggered at the end of a multi-row deletion.