We were maintaining temporary dev forks of golang.org/x/crypto/{acme,ssh}
in https://github.com/tailscale/golang-x-crypto instead of using
this repo's tempfork directory as we do with other packages. The reason we were
doing that was because x/crypto/ssh depended on x/crypto/ssh/internal/poly1305
and I hadn't noticed there are forwarding wrappers already available
in x/crypto/poly1305. It also depended internal/bcrypt_pbkdf but we don't use that
so it's easy to just delete that calling code in our tempfork/ssh.
This means we don't need another repo, for better or worse. (better:
one repo, worse: slightly more annoying to rebase to upstream, but not
terrible)
The acme package is moved unmodified.
This copies the code from tailscale/golang-x-crypto at git rev
3fde5e568a
Updates #8593
Updates #10238
Change-Id: I8af4378c04c1f82e63d31bf4d16dba9f510f9199
Signed-off-by: Brad Fitzpatrick <bradfitz@tailscale.com>