Bug 122869 Drag a parameter from data explorer view into a table in library, a new parameter is created automatically.
Description:Drag a parameter from data explorer view into a table in library, a new parameter is created automatically. Steps to reproduce: 1. Add a cascading parameter and a table in a library file. 2. Drag a parameter from data explorer view into a table cell in layout editor. 3. Find that a new parameter was added in data explorer view automatically.
UI/org.eclipse.birt.report.designer.ui/src/org/eclipse/birt/report/designer/internal/ui/dialogs/ExpressionTreeSupport.java
public static final String TREE_NAME_PARAMETERS = "Parameters"; 
	/**
	 * Creates all expression trees in default order
	 * 
	 * @param dataSetList
	 *            list for DataSet tree
	 */
	public void createDefaultExpressionTree( List dataSetList )
	{
		createFilteredExpressionTree( dataSetList, null );
	}
	/**
	 * Creates selected expression trees with given filter list.
	 * 
	 * @param dataSetList
	 *            list for DataSet tree
	 * @param filterList
	 *            list of filters
	 */
	public void createFilteredExpressionTree( List dataSetList, List filterList )
	{
		if ( filter( TREE_NAME_DATASETS, filterList ) )
		{
			createDataSetsTree( dataSetList );
		}
		if ( filter( TREE_NAME_PARAMETERS, filterList ) )
		{
			createParamtersTree( );
		}
		if ( filter( TREE_NAME_NATIVE_OBJECTS, filterList ) )