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.engine/src/org/eclipse/birt/chart/model/attribute/AttributePackage.java
* @see #getFontDefinition()
	 * @generated
	 */
	EAttribute getFontDefinition_WordWrap( );
	/**
	 * Returns the meta object for the containment reference '{@link org.eclipse.birt.chart.model.attribute.FontDefinition#getAlignment <em>Alignment</em>}'.
	 * <!-- begin-user-doc --> <!-- end-user-doc -->
	 * @return the meta object for the containment reference '<em>Alignment</em>'.
	 * @see org.eclipse.birt.chart.model.attribute.FontDefinition#getAlignment()
	 * @see #getFontDefinition()
	 * @generated
	 */
	EReference getFontDefinition_Alignment( );
	/**
	 * Returns the meta object for the attribute '{@link org.eclipse.birt.chart.model.attribute.FontDefinition#getRotation <em>Rotation</em>}'.
	 * <!-- begin-user-doc --> <!-- end-user-doc -->
	 * @return the meta object for the attribute '<em>Rotation</em>'.
	 * @see org.eclipse.birt.chart.model.attribute.FontDefinition#getRotation()
	 * @see #getFontDefinition()
	 * @generated
	 */
	EAttribute getFontDefinition_Rotation( );
	/**
	 * Returns the meta object for class '{@link org.eclipse.birt.chart.model.attribute.FormatSpecifier <em>Format Specifier</em>}'.
	 * <!-- begin-user-doc --> <!-- end-user-doc -->
	 * @return the meta object for class '<em>Format Specifier</em>'.
	 * @see org.eclipse.birt.chart.model.attribute.FormatSpecifier
	 * @generated
	 */
	EClass getFormatSpecifier( );