Bug 148181 Support deleting a directory from report document
Now Engine supports deleting a file from report document, and it would be nicer if deleting a directory could be also supported.
testsuites/org.eclipse.birt.report.tests.engine/src/org/eclipse/birt/report/tests/engine/api/RenderFolderDocumentTest.java
reportDoc=engine.openReportDocument(folderArchive);
			renderTask=engine.createRenderTask(reportDoc);
			
			htmlOption.setOutputFileName(htmlOutput);
			HTMLRenderContext renderContext = new HTMLRenderContext( );
			renderContext.setImageDirectory( "image" );
			HashMap appContext = new HashMap( );
			appContext.put( EngineConstants.APPCONTEXT_HTML_RENDER_CONTEXT,
					renderContext );
			
			renderTask.setRenderOption(htmlOption);
			renderTask.setAppContext( appContext );
			renderTask.setLocale( Locale.ENGLISH );
			renderTask.setPageRange( "All" );
			renderTask.render();
			renderTask.close();
			
			assertNotNull(docName+".html failed to render from folder-based document",htmlOutput);
			
		}catch(IOException ioe){
			ioe.printStackTrace();
			assertTrue("IOException (when render "+docName+" folder-based document)",false);
		}catch(EngineException ee){
			ee.printStackTrace();
			assertTrue("EngineException (when render "+docName+" folder-based document)",false);
		}
		
	}
}