all190406to1223: Add back proc_assoc and add to public api along with

enwiktionary 20190406
scraped on 20191127
indexed on 20191210
lextract MWEs (keyed_db) added on 20191215 https://github.com/frankier/lextract
clusters added on 20191223 https://github.com/frankier/finn-sense-clust

Using master branch at time of processing