Bug 16995 HoverHelp example does not create ON_TOP Shell for tooltips
The shell created to show the tooltip does not have the ON_TOP style. It causes the main window to loose focus when the tooltip is shown.
examples/org.eclipse.swt.examples/src/org/eclipse/swt/examples/hoverhelp/HoverHelp.java
tipLabelImage.setBackground(display.getSystemColor(SWT.COLOR_INFO_BACKGROUND));
			tipLabelImage.setLayoutData(new GridData(GridData.FILL_HORIZONTAL |
				GridData.VERTICAL_ALIGN_CENTER));
	
			tipLabelText = new Label(tipShell, SWT.NONE);
			tipLabelText.setForeground(display.getSystemColor(SWT.COLOR_INFO_FOREGROUND));
			tipLabelText.setBackground(display.getSystemColor(SWT.COLOR_INFO_BACKGROUND));
			tipLabelText.setLayoutData(new GridData(GridData.FILL_HORIZONTAL |
				GridData.VERTICAL_ALIGN_CENTER));
		}
	
		/**
		 * Enables customized hover help for a specified control
		 * 
		 * @control the control on which to enable hoverhelp
		 */
		public void activateHoverHelp(final Control control) {
			/*
			 * Get out of the way if we attempt to activate the control underneath the tooltip
			 */
			control.addMouseListener(new MouseAdapter () {
				public void mouseDown (MouseEvent e) {
					if (tipShell.isVisible()) tipShell.setVisible(false);
				}	
			});
	
			/*
			 * Trap hover events to pop-up tooltip
			 */
			control.addMouseTrackListener(new MouseTrackAdapter () {