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
* Sets the history entries
     */
    public void setHistoryEntries(IMethod[] elems) {
        fMethodHistory.clear();
        for (int i = 0; i < elems.length; i++) {
            fMethodHistory.add(elems[i]);
        }
        updateHistoryEntries();
    }
    /**
     * Gets all history entries.
     */
    public IMethod[] getHistoryEntries() {
        if (fMethodHistory.size() > 0) {
            updateHistoryEntries();
        }
        return (IMethod[]) fMethodHistory.toArray(new IMethod[fMethodHistory.size()]);
    }
    /**
     * Method setMethod.
     * @param method
     */
    public void setMethod(IMethod method) {
        if (method == null) {
            showPage(PAGE_EMPTY);
            return;
        }
        if ((method != null) && !method.equals(fShownMethod)) {
            addHistoryEntry(method);
        }