(FACT-613) Add structured processor fact

The first of these commits adds the 'processors' structured fact, which incorporates all processor-related facts into a nested hash. Includes keys for the equivalents of dynamic ProcessorX facts, ProcessorCount, and PhysicalProcessorCount.

In addition, the fact includes a 'ProcessorSpeed' key in OSX, which is equivalent to the existing sp_current_processor_speed fact.

The second commit refactors the existing Processor, ProcessorCount, PhysicalProcessorCount and dynamic ProcessorX flat facts to resolve by using values from the new 'processors' structured fact. This ensures that these facts will stay in sync with the new fact, while also maintaining backwards compatibility.
Yeah I was asking if there were any other supported kernels. I don't think there are, so I think we can remove this line.

And I don't think we can future proof against a weird new OS. Such a new OS would need support across the board, but future proofing all facts by confining them to all known OSs seems like overkill.  Basically YAGNI ;>