Bug 149617 Support Content-type-based editor lookup
UI/org.eclipse.birt.report.designer.ui/src/org/eclipse/birt/report/designer/ui/ReportPlugin.java
*         color depth for instance.
	 */
	public static ImageDescriptor getImageDescriptor( String key )
	{
		ImageRegistry imageRegistry = ReportPlugin.getDefault( )
				.getImageRegistry( );
		ImageDescriptor imageDescriptor = imageRegistry.getDescriptor( key );
		if ( imageDescriptor == null )
		{
			URL url = ReportPlugin.getDefault( ).find( new Path( key ) );
			if ( null != url )
			{
				imageDescriptor = ImageDescriptor.createFromURL( url );
			}
			if ( imageDescriptor == null )
			{
				imageDescriptor = ImageDescriptor.getMissingImageDescriptor( );
			}
			imageRegistry.put( key, imageDescriptor );
		}
		return imageDescriptor;
	}
	/**
	 * Relative to UI plugin directory, example: "icons/usertableicon.gif".
	 * 
	 * @param key
	 * @return an Image, do not dispose
	 */
	public static Image getImage( String key )
	{