In theory yes, but it is not yet "solid". This binding should be like... as loadProgress might peek to 100 before loading goes to false. So this should look like...


```
loaded: loadProgress === 100 && !loading
```
However, I didn't want to involve that change into this PR.

Handling those in C++ is a bit more laborious as it cannot be handled as binding instead needs to be done with two connects (and I was a bit lazy :( ). One slot that gets invoked when loadProgressChanged and  loadingChanged are emitted then masking the value out of those. I think that better home actually would be MozView itself? But I'd like to see that all works correctly before I push parts to MozView.