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/ElementPropertyDefn.java
* @return <code>false</code>.
	 */
	public boolean isReadOnly( )
	{
		return false;
	}
	/**
	 * Checks whether the property value can be edited by the user in the
	 * property sheet.
	 * 
	 * @return <code>true</code> if the property value is read-only,
	 *         <code>false</code> otherwise.
	 */
	public boolean isEditable( )
	{
		return !( getTypeCode( ) == PropertyType.CHOICE_TYPE );
	}
	/**
	 * Returns the method information of this property.
	 * 
	 * @return the method information of this property. Return null, if this
	 *         property is not a method property.
	 */
	public MethodInfo getMethodInfo( )
	{
		if ( getTypeCode( ) == PropertyType.SCRIPT_TYPE )
			return (MethodInfo) details;
		return null;
	}
}