B-77841 - Create a filter that redacts private attributes

- The filter current references /etc/repose/usage-schema/rm_private_attrs_for_obs.xsl which is installed through usage-schema
I was actually thinking to remove the use of java.nio.Files. Because I think JDK7 is just out to Prod last Friday. If we have some problems that we need to put back JDK6, then this whole code will break and it's a lot more painful to back out our filter. What do you think? Am I just having PTSD from last weekend, you think?