add corpus (de)compression changes to CHANGELOG
add corpus (de)compression changes to CHANGELOG

jaksmid/gensim,markroxor/gensim,mattilyra/gensim,olavurmortensen/gensim,tzoiker/gensim,ziky90/gensim,Kreiswolke/gensim,ziky90/gensim,laic/gensim,robotcator/gensim,akutuzov/gensim,macks22/gensim,bhargavvader/gensim,loisaidasam/gensim,gojomo/gensim,robotcator/gensim,gojomo/gensim,ELind77/gensim,markroxor/gensim,ELind77/gensim,bhargavvader/gensim,gojomo/gensim,pombredanne/gensim,ziky90/gensim,mattilyra/gensim,summanlp/gensim,quole/gensim,zachmayer/gensim,davechallis/gensim,jaksmid/gensim,RaRe-Technologies/gensim,bhargavvader/gensim,robotcator/gensim,dsquareindia/gensim,summanlp/gensim,loisaidasam/gensim,davechallis/gensim,olavurmortensen/gensim,olavurmortensen/gensim,pombredanne/gensim,akutuzov/gensim,loisaidasam/gensim,RaRe-Technologies/gensim,gojomo/gensim,laic/gensim,quole/gensim,davechallis/gensim,quole/gensim,macks22/gensim,manasRK/gensim,markroxor/gensim,dsquareindia/gensim,tzoiker/gensim,Kreiswolke/gensim,zachmayer/gensim,mattilyra/gensim,piskvorky/gensim,macks22/gensim,piskvorky/gensim,akutuzov/gensim,dsquareindia/gensim,ELind77/gensim,isohyt/gensim,piskvorky/gensim,manasRK/gensim,RaRe-Technologies/gensim,summanlp/gensim,isohyt/gensim,isohyt/gensim,pombredanne/gensim,jaksmid/gensim,RaRe-Technologies/gensim,Kreiswolke/gensim,zachmayer/gensim,manasRK/gensim,tzoiker/gensim,laic/gensim