Description of problem:
There is already an RFE for specifying bind credentials, however the code assumes that username (for example) will match against an attribute called "uid".
See the ldap_filter in the function lookup_user in pulp/platform/src/pulp/server/auth/ldap_connection.py

This may not be true for all LDAP servers, for example Active Directory.

Version-Release number of selected component (if applicable):
2.1

How reproducible:
Always

Steps to Reproduce:
1. Have an LDAP server where username is not in an attribute called "uid"
2. LDAP authentication wont work because the user wont be found.
3.

Actual results:
Can't actually get this far, because we can't bind to AD with credentials yet.

Expected results:
Specify uid attribute as sAMAccountName
and others too, like:
gecos = displayName


Additional info:
Need to link this up with Bug 817063, since there is no point getting this done before that one; well for AD support anyway.