The old headers were moved into folders because doing so avoids polluting
the system include directories.
Folder names were also normalized to lowercase.
Added callback scheme for a pass through to something higher
level. Since the ID is embedded into the arbitration ID, and some
devices can use different schemes whether it is plugged in through a
device or put into the daisy chain (pigeonImu), I made one "internal
data object" for max reusability.
