Node.ext.ldap

------------------

- Switch to use mdb as default db for slapd i testing layer.
[jensens]

- fix tests, where output order could be random.
[jensens]

------------------

- make db-type in test layer configurable
[jensens]

------------------

- Turning referrals off to fix problems with MS AD if it contains aliases.
[alexsielicki]

- Fix search to check list of binary attributes directly from the root node
data (not from attr behavior) to avoid unnecessarily initializing attribute
behavior just a simple search
[datakurre]

- Fix to skip group DNs outside the base DN to allow users' memberOf
attribute contain groups outside the group base DN
[datakurre]

------------------

- Add a ``batched_search`` generator function, which do the actual batching for us.
Use this function internally too.
[jensens, rnix]

- In testing set size_limit to 3 in ``slapd.conf`` in order to catch problems with batching.
[jensens, rnix]

- Fix missing paging in UGM group mapping method ``member_ids``.
[jensens]

------------------

- Minor code cleanup
[jensens]

- Paginate LDAP node ``__iter__``.
[jensens, rnix]

------------------

- Remove ``ILDAPProps.check_duplicates`` respective
``LDAPProps.check_duplicates``.
[rnix]

- ``rdn`` can be queried via ``attrlist`` in ``LDAPNode.search`` explicitely.
[rnix]

- Introduce ``get_nodes`` keyword argument in ``LDAPNode.search``. When set,
search result contains ``LDAPNode`` instances instead of DN's in result.
[rnix]

- ``LDAPNode.search`` returns DN's instead of RDN's in result. This fixes
searches with scope SUBTREE where result items can potentially contain
duplicate RDN's.
[rnix]

- Introduce ``node_by_dn`` on ``LDAPNode``.
[rnix]

- remove bbb code: no python 2.4 support (2.7+ now), usage of LDAPProperties
mandatory now.
[jensens]

- Overhaul LDAP UGM implementation.
[rnix]

- LDAP Node only returns direct children in ``__iter__``, even if search
scope subtree.
[rnix]

- LDAPNode keys cannot be aliased any longer. Removed ``_key_attr`` and
``_rdn_attr``.
child.

- LDAPNode does not provide secondary keys any longer. Removed
``_seckey_attrs``.
[rnix]

- Deprecate ``node.ext.ldap._node.AttributesBehavior`` in favor of
``node.ext.ldap._node.LDAPAttributesBehavior``.
[rnix]

- Remove deprecated ``node.ext.ldap._node.AttributesPart``.
[rnix]

- Don't fail on ``UNWILLING_TO_PERFORM`` exceptions when authenticating. That
might be thrown, if the LDAP server disallows us to authenticate an ``admin``
user, while we are interested in the local ``admin`` user.
[thet]

- Add ``ignore_cert`` option to ignore TLS/SSL certificate errors for self
signed certificates when using the ``ldaps`` uri schema.
[thet]

- Housekeeping.
[rnix]