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/command/ContentCommand.java
*            <code>true</code> to avoid the exception when the
	 *            <code>content</code> is a virtual element. Otherwise,
	 *            <code>false</code>.
	 * @throws SemanticException
	 *             if this content cannot be removed from container.
	 */
	public void remove( DesignElement content, int slotID,
			boolean unresolveReference, boolean flag ) throws SemanticException
	{
		doRemove( content, slotID, unresolveReference, flag );
	}
	/**
	 * @see #remove(DesignElement, int, boolean)
	 * @param content
	 *            the element to remove
	 * @param slotID
	 *            the slot from which to remove the content
	 * @param unresolveReference
	 *            status whether to un-resolve the references
	 * @param flag
	 *            Use the flag to indicate whether this method is do with the
	 *            element itself or do with its contents.
	 * @throws SemanticException
	 *             if this content cannot be removed from container.
	 */
	private void doRemove( DesignElement content, int slotID,
			boolean unresolveReference, boolean flag ) throws SemanticException
	{
		assert content != null;