Use the new tldap methods.

Previously karaage depended on placard, however this also pulled in
stuff that isn't appropriate for karaage anymore. e.g. tests. Moved
this to tldap.

This change doesn't yet handle upgrading tldap_counters correctly. That
is complicated by the fact the migrations live in placard, which is no
longer in INSTALLED_APPS.

Change-Id: Ib1997dd030041a28e3ada16ff04691f18859edf2