Bug 187213 Provid a writer to serialize design in document without any white space.
Add a new writer for serialize design in document without any withe space.
model/org.eclipse.birt.report.model.tests/test/org/eclipse/birt/report/model/writer/DocumentUtilTest.java
public void testSerializeExternalString( ) throws Exception
	{
		openDesign( "DocumnetUtilTest_ExternalResource.xml" ); 
		assertNotNull( designHandle );
		serializeDocument( );
		assertTrue( compareFile( "DocumentUtilTest_golden_5.xml" ) );  
	}
	/**
	 * For extended item, the extension name must be set first. So that, other
	 * properties can be set propertyly.
	 * 
	 * @throws Exception
	 */
	public void testExtendedItem( ) throws Exception
	{
		openDesign( "DocumentUtilTest_ExtendedItem.xml" ); 
		assertNotNull( designHandle );
		serializeDocument( );
		ExtendedItemHandle matrix1 = (ExtendedItemHandle) designHandle
				.findElement( "matrix1" ); 
		assertNotNull( ( (ExtendedItem) matrix1.getElement( ) ).getExtDefn( ) );
		assertTrue( compareFile( "DocumentUtilTest_golden_6.xml" ) ); 
	}
	/**
	 * Writes the document to the internal output stream.
	 * 
	 * @throws Exception
	 */
	private void serializeDocument( ) throws Exception
	{