Bug 36519 [call hierarchy] ability to copy the view's content to the clipboard
we should add the ability to copy the view's content to the clipboard (it may be useful for people to take a pic of the callgraph and show to other people, for example)
org.eclipse.jdt.ui/ui/org/eclipse/jdt/internal/ui/callhierarchy/CallHierarchyViewPart.java
initImplementorsMode();
        if (fMemento != null) {
            restoreState(fMemento);
        }
        
        initDragAndDrop();      
    }
    /**
     * @param PAGE_EMPTY
     */
    private void showPage(int page) {
        if (page == PAGE_EMPTY) {
            fPagebook.showPage(fNoHierarchyShownLabel);
        } else {
            fPagebook.showPage(fHierarchyLocationSplitter);
        }
        enableActions(page != PAGE_EMPTY);
    }
    /**
     * @param b
     */
    private void enableActions(boolean enabled) {
        fLocationContextMenu.setEnabled(enabled);
         
    }
    /**
     * Restores the type hierarchy settings from a memento.
     */
    private void restoreState(IMemento memento) {
        Integer orientation= memento.getInteger(TAG_ORIENTATION);