Bug 136833 Group key is affected by Generate All button in group.
Description: Group key is affected by Generate All button in group. Steps to reproduce: 1. Insert a list 2. Add a group, select a group key, then click Generate All button. Actual result: Group key disappeared, you have to reset it.
UI/org.eclipse.birt.report.designer.ui/src/org/eclipse/birt/report/designer/ui/dialogs/GroupDialog.java
final private static IChoice sortByAscending = DesignEngine.getMetaDataDictionary( )
			.getChoiceSet( DesignChoiceConstants.CHOICE_SORT_DIRECTION )
			.findChoice( DesignChoiceConstants.SORT_DIRECTION_ASC );
	final private static IChoice sortByDescending = DesignEngine.getMetaDataDictionary( )
			.getChoiceSet( DesignChoiceConstants.CHOICE_SORT_DIRECTION )
			.findChoice( DesignChoiceConstants.SORT_DIRECTION_DESC );
	final private static String SORT_GROUP_TITLE = DEUtil.getPropertyDefn( ReportDesignConstants.TABLE_GROUP_ELEMENT,
			GroupHandle.SORT_DIRECTION_PROP )
			.getDisplayName( );
	final private static IChoice[] pagebreakBeforeChoicesAll = DesignEngine.getMetaDataDictionary( )
			.getChoiceSet( DesignChoiceConstants.CHOICE_PAGE_BREAK_BEFORE )
			.getChoices( );
	final private static IChoice[] pagebreakAfterChoicesAll = DesignEngine.getMetaDataDictionary( )
			.getChoiceSet( DesignChoiceConstants.CHOICE_PAGE_BREAK_AFTER )
			.getChoices( );
	final private static IChoice[] intervalChoicesString = getIntervalChoicesString( );
	final private static IChoice[] intervalChoicesDate = getIntervalChoicesDate( );
	final private static IChoice[] intervalChoicesNumeric = getIntervalChoicesNumeric( );
	private static IChoice[] intervalChoices = intervalChoicesAll;
	private String previoiusKeyExpression = ""; 
	private Button repeatHeaderButton;
	private Combo pagebreakAfterCombo;
	private Combo pagebreakBeforeCombo;
	/**
	 * Constructor.
	 * 
	 * @param parentShell
	 */
	public GroupDialog( Shell parentShell, String title )
	{