MAHOUT-1343: JSON output format support in cluster dumper

git-svn-id: https://svn.apache.org/repos/asf/mahout/trunk@1538406 13f79535-47bb-0310-9956-ffa450edef68
Mahout-1343: monor code cleanups

git-svn-id: https://svn.apache.org/repos/asf/mahout/trunk@1538421 13f79535-47bb-0310-9956-ffa450edef68
Mahout-1343: more minor cleanups

git-svn-id: https://svn.apache.org/repos/asf/mahout/trunk@1538424 13f79535-47bb-0310-9956-ffa450edef68
MAHOUT-1325 Change remaining hadoop dependent tests to work out of a directory that is not under /tmp (isabel via sslavic)

git-svn-id: https://svn.apache.org/repos/asf/mahout/trunk@1538438 13f79535-47bb-0310-9956-ffa450edef68