[IO] Submitted IO-198 Patch to Add File Filtering to Lists, Sets, and Maps

[Michael Wooten]

I've submitted an idea for a new feature, including a patch with unit tests,
for updating FileFilterUtils to include methods for filtering Lists, Sets,
and Maps of Files using IOFileFilters.

These JIRA entry is available here:
http://issues.apache.org/jira/browse/IO-198

I'm new to the contribution process, so I would love any feedback.

Thanks!

-Michael Wooten