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
* 
	 * @param sVarName
	 * @throws ChartException
	 */
	public final void registerVariable( String sVarName, Object var )
			throws ChartException
	{
		Context.enter( );
		try
		{
			final Object oConsole = Context.javaToJS( var, scope );
			scope.put( sVarName, scope, oConsole );
		}
		finally
		{
			Context.exit( );
		}
	}
	/**
	 * Unregister a variable from current JavaScript context.
	 * 
	 * @param sVarName
	 * @throws ChartException
	 */
	public final void unregisterVariable( String sVarName )
			throws ChartException
	{
		scope.delete( sVarName );
	}
	/**