Bug 134954 Library can't be removed
Steps to reproduce: 1.New a report "a.rptdesign" 2.New a library which is not in the same fold with report, saying "../test/lib.rptlibrary" 3.Report includes the library 4.Remove the library Expected result: The library is removed Actual result: Open XMLSource, the included library structure is still there.
model/org.eclipse.birt.report.model/src/org/eclipse/birt/report/model/command/LibraryCommand.java
*         the id of extends child. Each value is another map of which the
	 *         key is the base id of virtual element and the value is property
	 *         name/value pair.
	 * @throws SemanticException
	 *             if error occurs during removing virtual elements.
	 */
	private Map dealElementDecendents( Library library, DesignElement parent,
			int actionCode ) throws SemanticException
	{
		List allDescendents = new ArrayList( );
		getAllDescdents( parent, allDescendents );
		Map overriddenValues = new HashMap( );
		for ( int i = 0; i < allDescendents.size( ); i++ )
		{
			DesignElement child = (DesignElement) allDescendents.get( i );
			do
			{
				if ( child.getRoot( ) != module )
					continue;
				if ( actionCode == RELOAD_ACTION )
				{
					Map values = unresolveElementDescendent( module, child );
					overriddenValues.put( new Long( child.getID( ) ), values );
				}
				if ( actionCode == SIMPLE_ACTION )
					throw new LibraryException(
							library,
							new String[]{child.getHandle( module )
									.getDisplayLabel( )},
							LibraryException.DESIGN_EXCEPTION_LIBRARY_HAS_DESCENDENTS );