> All input is merged into single dir:
> *cp -R ${WORK_DIR}/20news-bydate*/*/* ${WORK_DIR}/20news-all*
as well the above line should read as follows.
$ cp -R ${WORK_DIR}/20news-bydate/*/* ${WORK_DIR}/20news-all
see: http://mahout.apache.org/users/classification/twenty-newsgroups.html
