Replace pnProduct with a (very) thin CoreLib plProduct wrapper around CMake-defined product ID values
Fix issues from review
Merge pull request #265 from zrax/product-id

Replace pnProduct with CMake settings
Refactor RegistryKeyList

This is in preparation for page patching. The old code kept dynamic
(programatically created) and serialized keys separate. This had the
potential to reorder the key list during the application of a patch.

This is separate from the prp-patches branch to facillitate review.