Combine the tokens before doing expensive things to them

It seems to be faster to hash one huge string than many smaller ones that
total to the same length.  Also by only showing one final hash we remove O(N)
show calls.

The old and new fingerprints are not compatible but I haven't deployed this
in production anywhere yet so that doesn't bother me.  Had I, we'd need some
kind of versioning scheme for fingerprint computation I suppose.