Provide config file fields for enable users in LDAP backend

[Adam Young]

To fully implement the enabled check in LDAP, the config file needs to say two things:

1. Which attribute indicates that a user is enabled or disabled
2. What value or values for that attribute indicate a user is enabled or disabled.

In addition, disabling a user might require a custom LDAPmodify call.

For some complex setups, checking for disabled users might require a more complex query. If so, we'll cover that in a different ticket.

[Jose Castro Leon (jose-castro-leon)]

In Active Directory there is a field that implements that shows the status the account as well as much more data.
In this case if userAccountControl user attribute equals 2, then the account is disabled.

The only issue is that the user may not be allowed to do a simple_bind if the account is disabled.

http://support.microsoft.com/kb/305144/en

[OpenStack Infra (hudson-openstack)]

Fix proposed to branch: master
Review: https://review.openstack.org/14964

[OpenStack Infra (hudson-openstack)]

Reviewed: https://review.openstack.org/14964
Committed: http://github.com/openstack/keystone/commit/001f708e7d9ffc69c80f823e7ab5f79325cc8a40
Submitter: Jenkins
Branch: master

commit 001f708e7d9ffc69c80f823e7ab5f79325cc8a40
Author: Jose Castro Leon <email address hidden>
Date: Mon Oct 29 15:07:58 2012 +0100

    Provide config file fields for enable users in LDAP backend (bug1067516)

    DocImpact

    Change-Id: I1ee9a1e2505cdd8c9ee8acba5c0e89a4f25c7262