1.2.0

CHANGES:

Provide thread safety (Unix.fork and multi-domain safe) RNG generators by using
getrandom/getentropy on UNIX (or /dev/urandom). In your UNIX applications,
please use the "mirage-crypto-rng.unix" dependency and call
"Mirage_crypto_rng_unix.use_default ()" (instead of depending on
mirage-crypto-rng-{lwt,eio,async} and calling
"Mirage_crypto_rng_{eio,lwt,async}.initialize".

• mirage-crypto-rng: handle CPU_RNG failures (#255 @hannesm, addresses #251 #252
  #253)
• mirage-crypto-rng.unix: provide two generators: Urandom and Getentropy
  (#250 @hannesm @reynir @edwintorok, addresses #249)
• mirage-crypto-rng: deprecate the initialize for lwt, async, eio (and
  advertise Mirage_crypto_rng_unix.use_default () (#254 @hannesm)
• mirage-crypto-rng-eio: declare the cstruct dependency (#247 @hannesm)
• include "windows.h" (all lowercase) (#248 @mefyl)