clear the password even after a mismatch

Ignore SIGINT in master process, so editor won't quit because parent has gone away.

Remove as target from syslog line. The utilization was based on a flaky premise and doesn't add any useful information

Only close the fd if its actually open.

Slightly clearer error message on !permit.

Do proper return value checking around close.

Do seteuid check for clearer error message.

Allow vias to do config file checking without specifying a file.

Use waitpid instead of wait, since it's better practice.

Change ruid back to original value before calling authuser. TIOCCHKVERAUTH comares the ruids, which made doas and vias logout one another.

Remove all OpenBSD headers to distantiate this code from the project. Add a README that warns of the risks.

Import vias