Removed obsolete method and reduced method visibility.

The old, hard-coded locate() method is no longer used; it has been fully
replaced by the new one which uses the customizable location strategy.
The method obtainFileSystem() is only used within the io package, so its
visibility could be reduced.

git-svn-id: https://svn.apache.org/repos/asf/commons/proper/configuration/trunk@1527239 13f79535-47bb-0310-9956-ffa450edef68