KNOX-367: add support for new config param userSearchAttributeName
(cherry picked from commit 40dd1984971c96e4255ad95f093ae6309d4c0853)
KNOX-370: add support for new config param userObjectClass
(cherry picked from commit 25fc2375eb7c84de88ec6e2a1ee254346db58a11)
KNOX-368: add support for new config param userSearchBase
(cherry picked from commit 2759abe4766849f506d95268f0e16a604ea55c80)
KNOX-369: add support for new config param groupSearchBase
(cherry picked from commit 5de7465b2505b4c49f0c37d93aabc368eb6abc18)
KNOX-371: group membership lookup need to use userdn computed by search
(cherry picked from commit a0efb4b4c15cb0a223e33cae1c21027b02f408dc)
KNOX-372: add unit tests to check default values for userSearchAttributeName, userObjectClass
(cherry picked from commit b1179de9b6e7f775919829627e44c5cc975aa6a5)
KNOX-373: add unit tests to verify default values for userSearchBase, groupSearchBase
(cherry picked from commit 4db63daf4e554ce848f372b98bb033e0032e5cd2)
KNOX-374: KnoxLdapRealm does not default values correctly for userSearchBase and groupSearchBase
(cherry picked from commit 0d82b57270dc5d46af5314d738361ff84ac9609d)