Initial version from Emilia.
Ignore html
Add text target.
Twiddling.
Strengthen Merkle trees.
Add a couple of half-baked headers.
revised headers
Update doc to cover the empty tree case.
Sha256
Implement SHA-256 SerialHasher
Implement TreeHasher.
Tidy.
Merkle trees v0.1
Merkle trees and paths.
Include fixit: stddef.h for size_t
Merkle path verifiers
Add dependencies and optimisation.
Document Merkle paths.
Merge.
[mq]: consistency-proof