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
scale = container.getScale( );
			lToP = LAYOUT_TO_PPT_RATIO / scale;
			hTextSpace = (int) ( H_TEXT_SPACE * scale );
			vTextSpace = (int) ( V_TEXT_SPACE * scale );
			newPage( container );
			containerStack.push( new ContainerPosition( 0, 0 ) );
		}
		else
		{
			drawContainer( container );
			ContainerPosition pos;
			if ( !containerStack.isEmpty( ) )
			{
				pos = (ContainerPosition) containerStack.peek( );
				ContainerPosition current = new ContainerPosition( pos.x
						+ container.getX( ), pos.y + container.getY( ) );
				containerStack.push( current );
			}
			else
			{
				containerStack.push( new ContainerPosition( container.getX( ),
						container.getY( ) ) );
			}
		}
	}
	/**
	 * This method will be invoked while a containerArea ends.
	 * 
	 * @param container
	 *            the ContainerArea specified from layout