More than 20 collocations

[processo]

Is your feature request related to a problem? Please describe.
The collocation list is limited to 20 and sometimes I would like to see more.

Describe the solution you'd like
Maybe increase it to 50 or 100, or add a setting how many to find.

Describe alternatives you've considered
2-grams in Preprocess with raw counts, but that's not probabilistic association.
Frequent itemsets, but that does not consider only neighbors.

Additional context
The limit is set here:

orange3-text/orangecontrib/text/widgets/owcollocations.py

Line 186 in 71c4318

self.collModel[:] = np.hstack(self.results)[:20]