Use of top-level methods from Rake is deprecated

There are a few places where we expect that the top-level Rake methods will be defined in all situations. Some point after we made this library, Rake was modified to not pollute the toplevel namespace unless you were in a Rakefile. We need to make modifications to no longer use those methods at the top-level and instead fully-qualify them in some other namespace.

@enebo may have ideas here.