Provide more detailed error messages

It would be nice to get more details on the errors that this module experiences. I kept getting this error:
Authentication with the LDAP server for the dn [dn here] and saved password failed.

I had to run Wireshark to see that the LDAP server's DNS name was incorrect. (We have arcane names here, so it's hard to spot.) It would be nice for this information to be presented upfront.

Only caveat is this information is privileged and should only be revealed to those with a "need to know." Error details should be suppressed for all other users.