Escape glob characters for FileFinder's withSuffix() and withName()

Summary: Depends on D18980. When you search for files withSuffix('t*t'), that should match that suffix, literally, in a portable way.

Test Plan: Added unit tests and made them pass.

Reviewers: amckinley

Reviewed By: amckinley

Differential Revision: https://secure.phabricator.com/D18981