Initial size incorrect

[bartbutenaers]

Sometimes the BabylonJs progress bar does not nicely fit the available space. Instead it is being displayed much too small, on the left side of the widget.

I have the impression that this happens when multiple scenes on a single page. Seems that the timeout (which I had added to solve this) has a period that is too small if multiple scenes need to be rendered.

It would be much better if I could replace the timer by some kind of load-complete-event ... Indeed the BabylonJs canvas should be created at the moment that this node's parent DIV element has its final size!