addPageHandler() added to allow register handlers on page events (hide,
show, ...). That functionality is needed in case of aggregation instead
of inheritance. Example:
page.addPageHandler(new JQMPageEvent.DefaultHandler() {
    @Override
    public void onShow(JQMPageEvent event) {
        super.onShow(event);
        loadData();
    }});
Merge pull request #44 from slavap/master

addPageHandler() added to allow register handlers on page events (hide, show, ...).