Merge branch 'ps/hash-cleanup'

Merge branch 'ps/hash-cleanup'

Further code clean-up on the use of hash functions.  Now the
context object knows what hash function it is working with.

* ps/hash-cleanup:
  global: adapt callers to use generic hash context helpers
  hash: provide generic wrappers to update hash contexts
  hash: stop typedeffing the hash context
  hash: convert hashing context to a structure