renaming these is fine, but from a release standpoint, it means that we have to bump the major version. Since this code is widely used, I will merge as is into a v3 branch and ask you to resubmit a pull request that does not break backward compatibility.

This can be done by adding params, but not removing them, such as

<pre>
class pam (
  ...
  # keep this
  $system_auth_ac_auth_lines  = undef,
  # add this
  $pam_auth_lines             = undef,
) {
  ...
}
</pre>