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/FillChooserComposite.java
SelectionListener,
		MouseListener,
		DisposeListener,
		KeyListener,
		FocusListener
{
	private transient Composite cmpContentInner = null;
	private transient Composite cmpContentOuter = null;
	private transient Composite cmpDropDown = null;
	private transient Composite cmpButtons = null;
	private transient FillCanvas cnvSelection = null;
	private transient Button btnDown = null;
	private transient Label lblTransparency = null;
	private transient Slider srTransparency = null;
	private transient Button btnCustom = null;
	private transient Button btnGradient = null;
	private transient Button btnImage = null;
	private static Color[] colorArray = null;
	private final String[] saImageTypes = new String[]{
			"*.gif", "*.jpg", "*.png" 
	};
	private transient boolean bGradientEnabled = true;
	private transient boolean bImageEnabled = true;
	private transient Fill fCurrent = null;
	private transient boolean bTransparencyChanged = false;
	private transient int iTransparency = 0;
	private transient Vector vListeners = null;