(FACT 614) Add structured operatingsystem fact

The first of these commits adds the 'operatingsystem_hash' (name very much pending) structured fact, which incorporates all operatingsystem-related facts into a nested hash. Includes keys for the equivalents of operatingsystem, osfamily, operatingsystemrelease, operatingsystemmajrelease, and the six lsb facts for Linux systems.

The second commit refactors the previously mentioned existing flat facts to resolve by using values from the new 'operatingsystem_hash' structured fact. This ensures that these facts will stay in sync with the new fact, while also maintaining backwards compatibility.
Yeah, I think so.  If there were more values (like breaking apart the version number into all of the components) it'd make sense to have a sub-hash, but with just two I think they should be top-level.