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/PPTEmitter.java
package org.eclipse.birt.report.engine.emitter.ppt;
import java.io.IOException;
import java.util.logging.Logger;
import org.eclipse.birt.report.engine.content.IAutoTextContent;
import org.eclipse.birt.report.engine.content.ICellContent;
import org.eclipse.birt.report.engine.content.IContainerContent;
import org.eclipse.birt.report.engine.content.IContent;
import org.eclipse.birt.report.engine.content.IDataContent;
import org.eclipse.birt.report.engine.content.IForeignContent;
import org.eclipse.birt.report.engine.content.IGroupContent;
import org.eclipse.birt.report.engine.content.IImageContent;
import org.eclipse.birt.report.engine.content.ILabelContent;
import org.eclipse.birt.report.engine.content.IListBandContent;
import org.eclipse.birt.report.engine.content.IListContent;
import org.eclipse.birt.report.engine.content.IListGroupContent;
import org.eclipse.birt.report.engine.content.IPageContent;
import org.eclipse.birt.report.engine.content.IReportContent;
import org.eclipse.birt.report.engine.content.IRowContent;
import org.eclipse.birt.report.engine.content.ITableBandContent;
import org.eclipse.birt.report.engine.content.ITableContent;
import org.eclipse.birt.report.engine.content.ITableGroupContent;
import org.eclipse.birt.report.engine.content.ITextContent;
import org.eclipse.birt.report.engine.emitter.IContentEmitter;
import org.eclipse.birt.report.engine.emitter.IEmitterServices;
import org.eclipse.birt.report.engine.layout.area.ITextArea;
import org.eclipse.birt.report.engine.layout.area.impl.PageArea;
/**
 * The class passes the report content object to PPT output stream.
 */
public class PPTEmitter implements IContentEmitter