Fix trees(images) scaling in course drawings and remove zooming/panning, as they are not working

![screenshot 2014-06-02 10 56 21](https://cloud.githubusercontent.com/assets/2392131/3145239/d10a4d4c-ea33-11e3-8250-5b3609d9f19b.png)

Now, compared to huge trees across the whole course (before)