Release RC for missing crates

[Sytten]

Hi!

Thanks for the hard work, I am tracking the release of rand_core with impatience but it will likely take another couple months.
Could we get RC releases for the crates that are missing like md4, md2, etc. in the meantime?
I am aware this is not a high priority.

Thanks!

[tarcieri]

Sure, I can cut prereleases of all of the hashes that are currently unreleased at -pre

[Sytten]

Thank you! Much appreciated