Bug 140620 Chart scripting errors are ignored
Write a chart with an invalid script, the execution simply ignores the script. This makes it difficult to debug scripting. The error message is also not precise and needs improvements.
chart/org.eclipse.birt.chart.device.extension/src/org/eclipse/birt/chart/device/image/JavaxImageIOWriter.java
IIOWriteWarningListener,
		IImageMapEmitter
{
	protected Image _img = null;
	protected Object _oOutputIdentifier = null;
	private Bounds _bo = null;
	private transient boolean _bImageExternallySpecified = false;
	private static ILogger logger = Logger.getLogger( "org.eclipse.birt.chart.device.extension/image" ); 
	private final static String NO_OP_JAVASCRIPT = "javascript:void(0);"; 
	private final static String POLY_SHAPE = "poly"; 
	/**
	 * Returns the output format string for this writer.
	 * 
	 * @return