Webclient: optimizer plan not showing up

It seems that a file is missing, my browser's JavaScript console logs the following:
```
GET http://localhost:8080/js/progressbar.js 404 (Not Found)
```
I used the 0.5 release.

---------------- Imported from GitHub ----------------
Url: https://github.com/stratosphere/stratosphere/issues/901
Created by: rmetzger
Labels: bug, gui, simple-issue,
Created at: Tue Jun 03 12:32:55 CEST 2014
State: open