Added $GROUPS_DN variable and made the constructor pull it from the INI file. Also added get_user_info() method which will return user information as well as get_group_list() method which will pull a list of groups, and is_user_member() method which is used to verify if a user is in a group for openLDAP. AD does not require the is_user_member() method as the member of field in AD provides that information.