Added support for the unary # prefix operator to define hashes in
compose.

- This creates a nice syntax for hashes, for example if you want to pass
  the hash of ABC to a function, you can do func(#ABC).  Hashes like
  this will get computed at compile time.
- You can still pass any uint value as before.
- Also cleaned up some formatting and sorting of pre-calculated hashes
  made from update_hashes.py.