Update to Commons Math 3.1 and fix sampling iterator test

git-svn-id: https://svn.apache.org/repos/asf/mahout/trunk@1427791 13f79535-47bb-0310-9956-ffa450edef68
Use Commons Math RNG. Remove uncommons-math dependency. Adjust all tests as best I can to account for the new sequence of random numbers

git-svn-id: https://svn.apache.org/repos/asf/mahout/trunk@1428081 13f79535-47bb-0310-9956-ffa450edef68
Merge pull request #1 from apache/trunk

Trunk