catch up with stdlib ed25519 key name changes

fix: rename cmpslice to eqslice

Makefile: fix install target

client_keyexch: tuple destructuring

ssh-agent: use net::socket and net::close

Signed-off-by: Sebastian <sebastian@sebsite.pw>

net::ssh: use correct server key for kex

kex: improve exchash generation

kex: finish key exchange

net::ssh: add more constants

Partially implement curve25519-sha256 kex

Set up client write framework

net::ssh: allocate initial client wbuf

Initial kex foundations

cmd/ssh: remove obsolete function call

net::ssh: add new_kexinit

Probably to be removed later

Order cipher suites et al by preference

net::ssh: initial cipher & kex infra

net::ssh: separate client & server MAC

net::ssh: further simplify client_read

net::ssh: improve max message length handling