Revert "Make tf/idf methods customizable in TfidfModel"
Revert "Make tf/idf methods customizable in TfidfModel"

This reverts commit 680ed0ed7a06ddcf40d56d7a00c70e57380b46e2.

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