Bug 194371 Use page emitter framework to implement ppt emitter.
In order to keep consistent with pdf and postscript, ppt need to use page emitter framework.
engine/org.eclipse.birt.report.engine.emitter.ppt/src/org/eclipse/birt/report/engine/emitter/ppt/PPTRender.java
pptOutput = null;
	}
	protected void endPage( ) throws IOException
	{
		String imageURI;
		
		for ( Iterator ite = currentImageContents.iterator( ); ite.hasNext( ); )
		{
			Object content = ite.next( );
			if ( content instanceof IImageContent )
			{
				IImageContent imageContent = (IImageContent) content;
				generateImageBytes( imageContent );
			}
			else if ( content instanceof String )
			{
				imageURI = (String) content;
				generateImageBytes( imageURI );
			}
			pptOutput.write( "\n\n".getBytes( ) );
		}
		pptOutput.write( "</p:slide></body></html>\n".getBytes( ) ); 
	}
	private void exportImageHeader( String imagekey ) throws IOException
	{
		pptOutput.write( "\n".getBytes( ) );
		pptOutput.write( "--___Actuate_Content_Boundary___\n".getBytes( ) ); 
		pptOutput.write( ( "Content-Location: file:/C:/___Actuate___/"
				+ (String) imageNames.get( imagekey ) + "\n" ).getBytes( ) );
		pptOutput.write( "Content-Transfer-Encoding: base64\n".getBytes( ) );