hash function for suunto solution

Hi,

The Suunto Solution seems to be the only dc that doesn't support fingerprints. This annoys me because I can't fully rely on dc_device_set_fingerprint(3) and I like that function.

So I've added a hash function that creates a suunto solution fingerprint, then added the infrastructure to set, compare, and pass to the caller.

Caveat emptor! I haven't tested it because I don't have a suunto solution.

Downsides to using a hash function? It might be duplicated. However, given that this is a 128 bit hash, that's not terribly likely.

If this is ok, I can update the docs to reflect that setting the fingerprint is fully supported.

Best,

Kristaps