* ADD new /src/common/crypto_rand.[ch] module.
* ADD new /src/common/crypto_util.[ch] module (contains the memwipe()
function, since all crypto_* modules need this).
* FIXES part of #24658: https://bugs.torproject.org/24658
This reduces the likelihood that I have made any exploitable errors
in the encoding/decoding.
This commit also imports the trunnel runtime source into Tor.