TreeTagger should not be in this repo

[reckart]

The TreeTagger license unfortunately does not allow redistribution unless you have a written permission from the author. You might want to consider removing it from the repo.

See the license file for tt:

...
The licensee has no right to give or sell the system to third
   parties without written permission from the licenser.
...

[gangeli]

Fair enough. There's no reason for it to be there to begin with, other than the fact that I used it for an experiment.