Bug 120216 Group dialog should be showed even dataset is not set.
- Add a table report item - do not set the data set - try creating a new table group. - An error is shown Expected behavior - As part of the template requirements, we dont want UI to do the validation. User should be able to go and define a group, even if the dataset is not defined.
UI/org.eclipse.birt.report.designer.ui/src/org/eclipse/birt/report/designer/ui/dialogs/GroupDialog.java
intervalRange = new Spinner( intervalArea, SWT.NONE );
		intervalRange.setLayoutData( new GridData( GridData.HORIZONTAL_ALIGN_FILL ) );
		intervalRange.setMinimum( 0 );
		intervalRange.setMaximum( Integer.MAX_VALUE );
		intervalRange.setStep( 1 );
	}
	/**
	 * Creates the group area
	 * 
	 * @param parent
	 *            the parent composite
	 */
	private void createGroupArea( Composite parent )
	{
		Composite composite = new Composite( parent, SWT.NONE );
		composite.setLayoutData( new GridData( GridData.FILL_HORIZONTAL
				| GridData.VERTICAL_ALIGN_BEGINNING ) );
		composite.setLayout( new GridLayout( ) );
		Group includeGroup = new Group( composite, SWT.NONE );
		includeGroup.setText( GROUP_DLG_HEADER_FOOTER_LABEL );
		includeGroup.setLayoutData( new GridData( GridData.FILL_HORIZONTAL ) );
		includeGroup.setLayout( new FillLayout( SWT.VERTICAL ) );
		Composite includeGroupComposite = new Composite( includeGroup, SWT.NONE );
		includeGroupComposite.setLayout( new GridLayout( ) );
		includeHeader = new Button( includeGroupComposite, SWT.CHECK );
		includeHeader.setText( GROUP_DLG_INCLUDE_HEADER_LABEL );
		includeFooter = new Button( includeGroupComposite, SWT.CHECK );
		includeFooter.setText( GROUP_DLG_INCLUDE_FOOTER_LABEL );
		if ( inputGroup instanceof ListGroupHandle )
		{