MAHOUT-1151 Object reuse in distributed ALS

git-svn-id: https://svn.apache.org/repos/asf/mahout/trunk@1453310 13f79535-47bb-0310-9956-ffa450edef68
MAHOUT-1151 Object reuse in distributed ALS, fixed typo

git-svn-id: https://svn.apache.org/repos/asf/mahout/trunk@1453315 13f79535-47bb-0310-9956-ffa450edef68
MAHOUT-1151, a few more fixes

git-svn-id: https://svn.apache.org/repos/asf/mahout/trunk@1453756 13f79535-47bb-0310-9956-ffa450edef68
MAHOUT-1151, a few more fixes

git-svn-id: https://svn.apache.org/repos/asf/mahout/trunk@1453760 13f79535-47bb-0310-9956-ffa450edef68
MAHOUT-1151 more optimizations

git-svn-id: https://svn.apache.org/repos/asf/mahout/trunk@1454389 13f79535-47bb-0310-9956-ffa450edef68