Bug 153040 Template definition should be removed after the report item is deleted
Steps to reproduce: 1.New a report, extends lib.label 2.Convert the label to template report item, and revert it back to the report item 3.Delete the label 4.Remove the included library Expected result: Library can be removed Actual result: A BIRT exception occurred. Plug-in Provider:Eclipse.org Plug-in Name:BIRT Model Plug-in ID:org.eclipse.birt.report.model Version:2.1.0.v20060808-0630 Error Code:Error.LibraryException.LIBRARY_HAS_DESCENDENTS Error Message:The library "Lib" can no be dropped because it has descendents "NewLabel" in the current module.
model/org.eclipse.birt.report.model/src/org/eclipse/birt/report/model/metadata/ExtensionModelPropertyDefn.java
* 
	 * @see org.eclipse.birt.report.model.metadata.PropertyDefn#getDisplayNameID()
	 */
	public String getDisplayNameID( )
	{
		return extProperty.getDisplayNameID( );
	}
	/*
	 * (non-Javadoc)
	 * 
	 * @see org.eclipse.birt.report.model.metadata.PropertyDefn#getName()
	 */
	public String getName( )
	{
		return extProperty.getName( );
	}
	/*
	 * (non-Javadoc)
	 * 
	 * @see org.eclipse.birt.report.model.metadata.PropertyDefn#getStructDefn()
	 */
	public IStructureDefn getStructDefn( )
	{
		if ( details instanceof StructureDefn )
			return (StructureDefn) details;
		List members = extProperty.getMembers( );
		if ( members == null )
			return null;
		StructureDefn struct = new StructureDefn( );
		Iterator iter = members.iterator( );