[curves] Code review request

[Ron Garret]

I’ve created a git repo with a fork of DJB’s TweetNaCl library:

https://github.com/rongarret/tweetnacl

Main changes:

1.  Code reformatted using clang-format, and partially commented

2.  Added some additional functionality, mainly the ability to hash streamed input (useful on embedded devices with limited memory, like the SC4-HSM :-)

Would very much appreciate code review and comments.  Thanks!

rg