A new test for text with tex commands

As mentioned in #417, that pull request does not solve all problems of interpreting tex strings. 
This new test figure shall illustrate the problems. 
Here an image of the new figure:
![newacid](https://cloud.githubusercontent.com/assets/2790591/4974662/ae9bea44-68ce-11e4-9fd3-fdb165f7b157.png)