Bug 104986 Backgound image uses an absolute path
Currently Chart uses an absolute path to indicate a backgournd image, that may cause the design unusable on other environments. Expected the background image can be definded in multiple ways like in report designer. e.g. URI(absolute path), File(relative path), Embedded Image(Encoded Image Data).
chart/org.eclipse.birt.chart.ui.extension/src/org/eclipse/birt/chart/ui/swt/composites/MarkerIconDialog.java
btnBrowse.addSelectionListener( this );
	}
	
	private void updateButton( )
	{
		btnOK.setEnabled( iconList.getSelectionCount( ) != 0 );
	}
	/**
	 * Preview the image when it is a local image file.
	 * @param fullPath
	 * 				Image absolute path without "file:///"
	 */
	private void preview( String fullPath )
	{
		previewCanvas.loadImage( fullPath );
	}
	/**
	 * Preview the image when it is an external image file.
	 * @param uri
	 * 			Image uniform resource locator with "http://"
	 */
	private void preview( URL uri )
	{
		previewCanvas.loadImage( uri );
	}
	
	/**
	 * @param path 
	 * @return Returns URL
	 */