WIP #35: added ldap group member list checking and results filtering.
#35 when an ldap returns uids fetch users using config[dir_uid_source]
Use the full dn to auth against openldap
Merge pull request #37 from SpiderOak/openldap_auth

Accepting for now, but we need more automagic in determining LDAP type. Fixes #35 well enough for now.