Unused import.

git-svn-id: https://svn.apache.org/repos/asf/commons/proper/math/trunk@1610138 13f79535-47bb-0310-9956-ffa450edef68
whitespace.

git-svn-id: https://svn.apache.org/repos/asf/commons/proper/math/trunk@1610140 13f79535-47bb-0310-9956-ffa450edef68
Factored Kth selector and pivoting strategy out from Percentile.

Thanks to Venkatesha Murthy for the patch.

JIRA: MATH-1120

git-svn-id: https://svn.apache.org/repos/asf/commons/proper/math/trunk@1610141 13f79535-47bb-0310-9956-ffa450edef68