If noninteractive_auth is set, authentication methods that do not
require input from the user's terminal may proceed. It is off by
default, which restores the pre-1.9.9 behavior of "sudo -n".
When logging terminal input, if log_passwords is disabled and any
of the regular expressions in the passprompt_regex list are found
in the terminal output, terminal input will be replaced with '*'
characters until a newline or carriage return is found in the input
or an output character is received.
This makes it possible to use a different PAM configuration for
when "sudo -A" is used. The main use case is to only use PAM modules
that can interact with the askpass program. GitHub issue #112.
