Fixes #3963: Explains how to search for user for LDAP authentication
Merge pull request #29 from fanf/bug_3963/allows_ldap_search_for_ldap_authn

Fixes #3963: Explains how to search for user for LDAP authentication
Merge branch 'branches/rudder/2.4' into branches/rudder/2.6
Merge branch 'branches/rudder/2.6' into branches/rudder/2.7