MAHOUT-1353 Visibility of preparePreferenceMatrix directory location

git-svn-id: https://svn.apache.org/repos/asf/mahout/trunk@1539672 13f79535-47bb-0310-9956-ffa450edef68
MAHOUT-1352 Option to change RecommenderJob output format

git-svn-id: https://svn.apache.org/repos/asf/mahout/trunk@1540012 13f79535-47bb-0310-9956-ffa450edef68