Bug 180701 [JFace] API - Popup dialog is creating image descriptors every time it is opened
We are not caching the imageDescriptors from PopupDialog but are recreating them all of the time. This is likely not a serious issue but it will generate garbage. Also the images are not looked up using bundles so they cannot be overridden in other Locales. As they are currently symmetric this is not an issue but they should be looked up in the same way we do it in JFaceResources when this fixed.
bundles/org.eclipse.jface/src/org/eclipse/jface/dialogs/PopupDialog.java
*/
	public final static int POPUP_MARGINWIDTH = 0;
	/**
	 * Margin height (in pixels) to be used in layouts inside popup dialogs
	 * (value is 0).
	 */
	public final static int POPUP_MARGINHEIGHT = 0;
	/**
	 * Vertical spacing (in pixels) between cells in the layouts inside popup
	 * dialogs (value is 1).  
	 */
	public final static int POPUP_VERTICALSPACING = 1;
	/**
	 * Vertical spacing (in pixels) between cells in the layouts inside popup
	 * dialogs (value is 1).
	 */
	public final static int POPUP_HORIZONTALSPACING = 1;
	/**
	 * 
	 */
	private static final GridLayoutFactory POPUP_LAYOUT_FACTORY = GridLayoutFactory
			.fillDefaults().margins(POPUP_MARGINWIDTH, POPUP_MARGINHEIGHT)
			.spacing(POPUP_HORIZONTALSPACING, POPUP_VERTICALSPACING);
	
	/**
	 * Border thickness in pixels.
	 */
	private static final int BORDER_THICKNESS = 1;
	/**
	 * The dialog's toolbar for the move and resize capabilities.