Move chef_wm_password to chef_objects/src/chef_password

* remove chef_wm_password and tests from this repo
* also remove chef_wm_authenticate_user, _users, _named_users and routing to them -
  it makes no sense to update these to use the updated password module,
  since these have been superceded by oc_chef_wm versions of the same.

ping @opscode/server-team