Fixed some warnings reported by IntelliJ.

git-svn-id: https://svn.apache.org/repos/asf/commons/proper/configuration/trunk@1590466 13f79535-47bb-0310-9956-ffa450edef68
[CONFIGURATION-577] Removed dependency to Commons Collections.

git-svn-id: https://svn.apache.org/repos/asf/commons/proper/configuration/trunk@1590467 13f79535-47bb-0310-9956-ffa450edef68
[CONFIGURATION-577] Updated changes.xml.

git-svn-id: https://svn.apache.org/repos/asf/commons/proper/configuration/trunk@1590468 13f79535-47bb-0310-9956-ffa450edef68