Results 4 issues of Ludovica Gonella

I added the features I created for Fireflax

To do: - [x] Make Wapiti BILOU compatible - [x] Add test for Wapiti with Bilou on - [x] Add test for wapiti.merge_top_n - [x] Add tests for grouping.py -...

these metrics are measured independently from where in the page the entity has been extracted. It also it checks full match only: ``accuracy(true = 'John Doe', pred = 'John' )``...