* Only direct invocation of cypto_hash_sha256 & crypto_hash_sha512 produced correct output.
* Some remaining header file mixups, so changed approach to wrapping the state structures.
* Fixes https://github.com/espressif/esp-idf/issues/1044 (crypto_sign problems)
* Add option to disable mbedTLS implementation for SHA256 & SHA512 in libsodium
Run some unit test cases based (poorly) around sodium's test infrastructure.
Increase in unity test task stack is due to signature tests, load a lot of data onto the stack.
