CS3343Group1/Acumen — pull request #21 by JasonYJWANG (2014-11-01 09:10:19+00:00)
Title: Version 5 - common words filter and IG list done

Filter the common used words and work out the correct information gain
for each words(NAN for useless words-appear in every essay). Need to
filter the characters other than A-Z and -.