## 2016-11-16 appendChild and document.write, #Jens

When using script tags to load external scripts, the browser waits for the first 
to load before loading the second. The result looks like this. 

```
Script1
Hello Wed Nov 16 2016 11:50:03 GMT+0100 (W. Europe Standard Time)
Script2
Hello Wed Nov 16 2016 11:50:03 GMT+0100 (W. Europe Standard Time)
Script3
Hello Wed Nov 16 2016 11:50:03 GMT+0100 (W. Europe Standard Time)
```

In our lively-container, we dynamically create script tags and add them to the 
dom and the result looks like this. 

```
Script1
Script2
Script3
Hello Wed Nov 16 2016 11:49:31 GMT+0100 (W. Europe Standard Time)
Hello Wed Nov 16 2016 11:49:31 GMT+0100 (W. Europe Standard Time)
Hello Wed Nov 16 2016 11:49:31 GMT+0100 (W. Europe Standard Time)
```

This (among some other issues) prevented blockly from loading in lively-container. So let's fix it.