Increase LDAP Authentication scope

Review Request #782 — Created March 24, 2009 and submitted — Latest diff uploaded

Review Board SVN (deprecated)
Changed the "scope" of LDAP authentication from SCOPE_ONELEVEL to SCOPE_SUBTREE

This allowed our company LDAP server to successfully authenticate against it.  My understanding is that this change should increase the schema's that RB authentication works with.

However, I am by no means an LDAP expert, I just know this is what it took to get it working on our server, and what our IT dept recommended.

Also, this URL of LDAP scope may be instructive:
Works on our company LDAP server.  Of course, I could not test it in other environments, so this change should be considered very carefully.