1. Bug fix: If Add option is not enabled then an extra column is added to the beginning of each row. This was fixed by checking whether edit or add is enabled during the construction of each row.
2. New feature : labels for each column. If the label is not set for a column i.e., left undefined or value is made '', then the title of the column from the DB is used.
3. Delete exposes callback function to remove delted row upon success of AJAX call performed outside.
4. More comments in code.