Prefix facts retrieved from mcollective with :: to indicate top level.

When hiera retrieves facts from mcollective it does not place them in the top level (by prefixing with ::). Because of this mcollective scope values will not match values in hiera.yaml that are in the form %{::fact}. This patch prefixes :: on all facts that are pulled from mcollective.
This makes these values no longer accessible as just `%{name}`.