Add a new sudoers settings log_passwords and passprompt_regex.

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.

plugins/sudoers/sudoers.c

@@ -1658,6 +1658,7 @@ set_callbacks(void)
     sudo_defs_table[I_MAILFROM].callback = cb_mailfrom;
     sudo_defs_table[I_MAILTO].callback = cb_mailto;
     sudo_defs_table[I_MAILSUB].callback = cb_mailsub;
+    sudo_defs_table[I_PASSPROMPT_REGEX].callback = cb_passprompt_regex;
 
     debug_return;
 }