Added animations; plus performance fix

• Eps images are not re-rendered on every goemtry change anymore, but just when the scale changes. Therefor resizing the window works with decent speed again.
• There is some code to animate changes in the worksheet. I am not yet quite sure which changes should be animated so that the experience is consistent and the user is not annoyed by too many (slow) animations. But I think that the animations can improve the experience of the user.