Bug 121498 When datasource/dataset deleted, the datasource/dataset property binding element haven't been deleted
When deleted the datasource/dataset, the datasource/dataset property binding element haven't been deleted. Expected result: This operation must be a transaction.
model/org.eclipse.birt.report.model/src/org/eclipse/birt/report/model/core/Module.java
return new ArrayList( libraries );
		return Collections.EMPTY_LIST;
	}
	/**
	 * Inserts the library to the given position.
	 * 
	 * @param library
	 *            the library to insert
	 * @param posn
	 *            at which the given library is inserted.
	 */
	public void insertLibrary( Library library, int posn )
	{
		if ( libraries == null )
			libraries = new ArrayList( );
		
		assert posn >= 0 && posn <= libraries.size( );
		libraries.add( posn, library );
	}
	/**
	 * Adds the given libray to library list.
	 * 
	 * @param library
	 *            the library to insert
	 */
	public void addLibrary( Library library )
	{
		if ( libraries == null )
			libraries = new ArrayList( );
		libraries.add( library );