[ale] how to create user with no password

[Doug McNash]

> 
> to realize that it is non-trivial and might not be trustworthy.
> 
> "info false" claims
> 

Compile 

main(){exit(1);} 

as false

I have not looked at the exit call for security holes but I thinks it's
pretty safe since no arguments are processed by main().

nologin looks pretty non-trivial too