Add results of Stanford's OpenIE, UW OpenIE, and MPI's ClausIE

[aoldoni]

• Stanford's: http://nlp.stanford.edu/software/openie.html
• UW's / AllenAI: http://openie.allenai.org/
• MPI: https://www.mpi-inf.mpg.de/departments/databases-and-information-systems/software/clausie/

[aoldoni]

This is already possible in the current tool for comparison.