mgnlRefresh is not available when the PageEditor first loads

The SPA app can load faster then the mgnlRefresh is added to the window, this will cause bugs if the app tries to use mgnlRefresh - but mgnlRefresh is not available yet. Namely, the green bars won't get rendered.

In practice, this problem won't occur that often because the SPA app will be also be making a call to the REST endpoints to load content before calling mgnlRefresh. But it can happen if the REST response is faster then the mgnlRefresh being added. 

Or a developer might have hardcoded some json fragments and might not make a REST call during some testing for example.