[COLLECTIONS-494] Move Equator interface to base package.

git-svn-id: https://svn.apache.org/repos/asf/commons/proper/collections/trunk@1540567 13f79535-47bb-0310-9956-ffa450edef68
[COLLECTIONS-494] Move Equator interface to base package.

git-svn-id: https://svn.apache.org/repos/asf/commons/proper/collections/trunk@1540568 13f79535-47bb-0310-9956-ffa450edef68