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
import java.io.InputStream;
import java.io.OutputStream;
import java.net.URL;
import java.nio.ByteBuffer;
import java.nio.charset.Charset;
import java.util.ArrayList;
import java.util.HashMap;
import java.util.Iterator;
import java.util.List;
import java.util.Map;
import java.util.Stack;
import java.util.TreeMap;
import java.util.logging.Level;
import java.util.logging.Logger;
import org.apache.batik.transcoder.TranscoderException;
import org.apache.batik.transcoder.TranscoderInput;
import org.apache.batik.transcoder.TranscoderOutput;
import org.apache.batik.transcoder.image.JPEGTranscoder;
import org.apache.commons.codec.binary.Base64;
import org.eclipse.birt.report.engine.api.IReportRunnable;
import org.eclipse.birt.report.engine.api.RenderOption;
import org.eclipse.birt.report.engine.api.script.IReportContext;
import org.eclipse.birt.report.engine.content.IImageContent;
import org.eclipse.birt.report.engine.content.IReportContent;
import org.eclipse.birt.report.engine.content.IStyle;
import org.eclipse.birt.report.engine.css.engine.StyleConstants;
import org.eclipse.birt.report.engine.css.engine.value.FloatValue;
import org.eclipse.birt.report.engine.emitter.IEmitterServices;
import org.eclipse.birt.report.engine.layout.area.IArea;
import org.eclipse.birt.report.engine.layout.area.IAreaVisitor;