Bug 214254 Expose Javascript "event" object for interactivity
When doing interactivity with a chart, and specifying a Mouse Click event with an Invoke Script action, the browser event object should be passed into the script. This object should be named "evt", and accompany the other standard category and value series parameters.
chart/org.eclipse.birt.chart.device.svg/src/org/eclipse/birt/chart/device/svg/SVGInteractiveRenderer.java
/**
	 * Indicates if onload method of data points has been added. This map is
	 * used for saving states of multiple series and data points.
	 */
	private Map mapOnloadAdded = new HashMap( );
	
	private int iFirstDataPointIndex = -1;
	public SVGInteractiveRenderer( ULocale locale )
	{
		if ( locale == null )
			this.locale = ULocale.getDefault( );
		else
			this.locale = locale;
	}
	public void setIUpdateNotifier( IUpdateNotifier iun )
	{
		this._iun = iun;
	}
	public void setSVG2D( SVGGraphics2D svg2D )
	{
		this.svg_g2d = svg2D;
	}
	/**
	 * Groups the svg drawing instructions that represents this primitive
	 * events. Each group is assigned an id that identifies the source object of
	 * the primitive event
	 * 
	 * @param pre
	 *            primitive render event
	 * @param drawText