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.engine/src/org/eclipse/birt/chart/device/IDeviceRenderer.java
* A property name that identifies an output format identifier
	 */
	public static final String FORMAT_IDENTIFIER = "device.output.format.identifier"; 
	/**
	 * A property name that identifies a device-specific graphics context
	 */
	public static final String GRAPHICS_CONTEXT = "device.output.context"; 
	/**
	 * A property name that identifies a device-specific visual component (e.g.
	 * used for event detection)
	 */
	public static final String UPDATE_NOTIFIER = "device.component"; 
	/**
	 * A property name that identifies the expected bounds of the chart being
	 * generated. This notification is sent out to provide the renderer with a
	 * hint about the location and size of the output being generated typically
	 * used with an Image file output. This is internally set by the
	 * 'Generator'.
	 */
	public static final String EXPECTED_BOUNDS = "device.bounds"; 
	/**
	 * A property name that identifies an instance of a cached java.awt.Image
	 * that may be passed in for potential reuse. In general, the image device
	 * renderers are configured to create a new image instance for every chart
	 * image generation request if a cached image is not specified. Ensure that
	 * the image passed in externally uses the correct size in pixels equivalent
	 * to the expected bounds specified in points.
	 */
	public static final String CACHED_IMAGE = "cached.image"; 
	/**