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/script/ScriptHandler.java
+ " *            IChartScriptContext\n" 
			+ " */\n" 
			+ "//function beforeDrawDataPoint( dph, fill, context ){}\n" 
			+ "\n" 
			+ "/**\n" 
			+ " * Called before rendering the label for each datapoint.\n" 
			+ " * \n" 
			+ " * @param dph\n" 
			+ " *            DataPointHints\n" 
			+ " * @param label\n" 
			+ " *            Label\n" 
			+ " * @param context\n" 
			+ " *            IChartScriptContext\n" 
			+ " */\n" 
			+ "//function beforeDrawDataPointLabel( dph, label, context ){}\n" 
			+ "\n" 
			+ "/**\n" 
			+ " * Called before rendering curve fitting.\n" 
			+ " * \n" 
			+ " * @param cf\n" 
			+ " *            CurveFitting\n" 
			+ " * @param context\n" 
			+ " *            IChartScriptContext\n" 
			+ " */\n" 
			+ "//function beforeDrawFittingCurve( cf, context ){}\n" 
			+ "\n" 
			+ "/**\n" 
			+ " * Called before rendering each label on a given Axis.\n" 
			+ " * \n" 
			+ " * @param axis\n"