Improve readability of add_copy_specs() usage in ldap.py

Use multi-line style for add_copy_specs() invocations in the ldap
plug-in per the recommendations in Issue #173.

Signed-off-by: Bryn M. Reeves <bmr@redhat.com>
Add pam_ldap.conf collection to ldap plug-in

Add the pam_ldap.conf file to the data collected by the ldap
plug-in and tidy up substitution strings for this plug-in.

Signed-off-by: Bryn M. Reeves <bmr@redhat.com>