Use crypto::random to generate key

Use unix::passwd instead of our own parsing

noecho for hinitramfs-cryptsetup

Create hinitramfs store if it doesn't exists

Revoke username key after first login

Keyring and key are more secure now

Don't print error message if keyring was not found

Handle result from nlplug-findfs

Don't show password when being typed

Rename cryptkey to key

The cryptkey would be the key for LUKS, however here we're storing the
key to the user's himitsu store.

Verify user and propagate uid

Generate random key for cryptsetup

Add missing newlines

Add hinitramfs-autologin to login as a specific user

Next step is to have /etc/hinitramfs/<uid>-<username> to support
multiple users.

Get device from caller

Add hinitramfs-cryptsetup

Add -p parameter to specify path to the store

Currently only to himitsud and a subset of himitsu-store.

Add hinitramfs-prompt as the prompt

Unlock secstore with passphrase from Linux keyring

Caveats:
- Linux only (duh)
- User passphrase must be in linux keyring, future goal should be to have
  either another passphrase OR the unencrypted key directly

himitsu-store: correctly restore termios

Fix termios not restored when terminated by fmt::fatal in init or
reencrypt