Bug 141959 Changing data set didn't clean old column bindings
Steps to reproduce: 1.Add two data sets, "ds1" and "ds2" 2.Add a table, binding with "ds1". All "ds1" column bindings generate automatically, that's good 3.Change "ds1" to None Expected result: All "ds1" column bindings should be cleaned Actual result: All "ds1" column bindings are still there. If changing to "ds2", "ds2" column bindings will be added after them.
UI/org.eclipse.birt.report.designer.ui/src/org/eclipse/birt/report/designer/ui/dialogs/ColumnBindingDialog.java
if ( isEnableAutoCommit( ) )
		{
			getActionStack( ).rollback( );
		}
	}
	private CommandStack getActionStack( )
	{
		return SessionHandleAdapter.getInstance( ).getCommandStack( );
	}
	private transient boolean enableAutoCommit = true;
	private List groupList;
	private String[] groups;
	public boolean isEnableAutoCommit( )
	{
		return enableAutoCommit;
	}
	/**
	 * @param enableAutoCommit
	 *            The enableAutoCommit to set.
	 */
	public void setEnableAutoCommit( boolean enableAutoCommit )
	{
		this.enableAutoCommit = enableAutoCommit;
	}
	private PropertyHandle getPropertyHandle( )
	{
		return inputElement.getPropertyHandle( ReportItemHandle.PARAM_BINDINGS_PROP );
	}
}