Bug 85774 [Presentations] bad tooltips in r21 presentation on Linux
The tooltips for the view menu and close buttons contain the "&" character on GTK.
bundles/org.eclipse.ui.presentations.r21/src/org/eclipse/ui/internal/presentations/R21BasicStackPresentation.java
* Does nothing if a tab already exists for the given part. 
     *
     * @param newPart
     * @param index
     */
    public void addPart(IPresentablePart newPart, int index) {
        
        if (getTab(newPart) != null) {
            return;
        }
        createPartTab(newPart, index);
        setControlSize();
    }
    /* (non-Javadoc)
     * @see org.eclipse.ui.internal.skins.StackPresentation#removePart(org.eclipse.ui.internal.skins.IPresentablePart)
     */
    public void removePart(IPresentablePart oldPart) {
        if (current == oldPart) {
        	titleLabel.setImage(null);
            current = null;
        }
        CTabItem item = getTab(oldPart);
        if (item == null) {
            return;
        }
        oldPart.setVisible(false);
        item.dispose();
        
        setControlSize();
    }